BSD-3-Clause licensed by Commercial Haskell SIG
Maintained by [email protected]
This version can be pinned in stack with:stack-2.9.1@sha256:ad3e4e2aa9bdc1bb9bc7b5f06a0c294bae73e6fb01d4c98341c7bdbfc4cd4306,19053

Module documentation for 2.9.1

The Haskell Tool Stack

Unit tests Integration tests Release

Stack is a cross-platform program for developing Haskell projects. It is intended for Haskellers both new and experienced.

See or the doc directory for more information.


You can participate with the Stack community in the following areas:




Changes since v2.7.5:

Behavior changes:

  • stack build --coverage will generate a unified coverage report, even if there is only one *.tix file, in case a package has tested the library of another package that has not tested its own library. See #5713
  • stack --verbose no longer includes the lengthy raw snapshot layer (rsl) in the debug output by default. The new stack --[no-]rsl-in-log flag enables or disables the inclusion of the rsl in the debug output.

Other enhancements:

  • Bump to Hpack 0.35.0.
  • On Windows, the installer now sets DisplayVersion in the registry, enabling tools like winget to properly read the version number.
  • Adds flag --script-no-run-compile (disabled by default) that uses the --no-run option with stack script (and forces the --compile option). This enables a command like stack --script-no-run-compile Script.hs to behave like stack script <arguments> --no-run --compile -- Script.hs but without having to list all the <arguments> in the Stack interpreter options comment in Script.hs on the command line. That may help test that scripts compile in CI (continuous integration). See #5755
  • Fuller help is provided at the command line if a subcommand is missing (for example, stack ls now yields the equivalent of stack ls --help). See #809
  • Add build option --cabal-verbosity=VERBOSITY to specify the Cabal verbosity level (the option accepts Cabal’s numerical and extended syntax). See #1369
  • Add the possibility of a sh script to customise fully GHC installation. See #5585
  • tools subcommand added to stack ls, to list stack’s installed tools.
  • stack uninstall shows how to uninstall Stack.
  • --ghc-variant accepts int-native as a variant.

Bug fixes:

  • Fix stack clean --full, so that the files to be deleted are not in use. See #5714
  • Fix an inconsistency in the pretty formatting of the output of stack build --coverage
  • Fix repeated warning about missing parameters when using stack new
  • Include pantry-0.5.6: Remove operational and mirror keys from bootstrap key set #53
  • Pass any CPP options specified via cpp-options: in the Cabal file to GHCi using GHC’s -optP flag. See #5608
  • On Unix-like operating systems, respect the with-gcc option when installing GHC. See #5609
  • Fixed logic in get_isa() in to exclude systems that don’t have x86 in their uname -m output. See 5792.
  • Fixed output of stack ls snapshots local on Windows, to behave like that on Unix-like operating systems.
  • Fix non-deterministic test failures when executing a test suite for a multi-project repository with parallelism enabled. See #5024


Changes since v2.7.3:

Behavior changes:

  • Cloning git repositories isn’t per sub-directory anymore, see #5411

Other enhancements:

  • stack setup supports installing GHC for macOS aarch64 (M1)

  • stack upload supports authentication with a Hackage API key (via HACKAGE_KEY environment variable).

Bug fixes:

  • Ensure that extra-path works for case-insensitive PATHs on Windows. See rio#237
  • Fix handling of overwritten ghc and ghc-pkg locations. #5597
  • Fix failure to find package when a dependency is shared between projects. #5680
  • stack ghci now uses package flags in stack.yaml #5434


Changes since v2.7.1:

Other enhancements:

  • stack upgrade will download from before trying See #5288
  • stack upgrade makes less assumptions about archive format. See #5288
  • Add a --no-run flag to the script command when compiling.

Bug fixes:

  • GHC source builds work properly for recent GHC versions again. See #5528
  • stack setup always looks for the unpacked directory name to support different tar file naming conventions. See #5545
  • Bump pantry version for better OS support. See pantry#33
  • When building the sanity check for a new GHC install, make sure to clear GHC_PACKAGE_PATH.
  • Specifying GHC RTS flags in the stack.yaml no longer fails with an error. #5568
  • stack setup will look in sandboxed directories for executables, not relying on `findExecutables. See GHC issue 20074
  • Track changes to setup-config properly to avoid reconfiguring on every change. See #5578


Changes since v2.5.1.1:

Behavior changes:

  • stack repl now always warns about GHCi problems with loading multiple packages. It also sets now proper working directory when invoked with one package. See #5421

  • custom-setup dependencies are now properly initialized for stack dist. This makes explicit-setup-deps no longer required and that option was removed. See #4006

Other enhancements:

  • Nix integration now passes ghcVersion (in addition to existing ghc) to shell-file as an identifier that can be looked up in a compiler attribute set.

  • Nix integration now allows Nix integration if the user is ready in nix-shell. This gets rid of “In Nix shell but reExecL is False” error.

  • stack list is a new command to list package versions in a snapshot. See #5431

  • Consider GHC 9.0 a tested compiler and remove warnings.

  • custom-preprocessor-extensions is a new configuration option for allowing Stack to be aware of any custom preprocessors you have added to Setup.hs. See #3491

  • Added --candidate flag to upload command to upload a package candidate rather than publishing the package.

  • Error output using --no-interleaved-output no longer prepends indenting whitespace. This allows emacs compilation-mode and vim quickfix to locate and track errors. See #5523

Bug fixes:

  • stack new now supports branches other than master as default for GitHub repositories. See #5422

  • Ignore all errors from hi-file-parser. See #5445 and #5486.

  • Support basic auth in package-indices. See #5509.

  • Add support for parsing .hi. files from GHC 8.10 and 9.0. See hi-file-parser#2.


Hackage-only release:

  • Support build with persistent-2.11.x and optparse-applicative-0.16.x


Changes since v2.3.3

Major changes:

  • Add the snapshot-location-base yaml configuration option, which allows to override the default location of snapshot configuration files. This option affects how snapshot synonyms (LTS/Nightly) are expanded to URLs by the pantry library.

  • docker-network configuration key added to override docker --net arg

Behavior changes:

  • File watching now takes into account specified targets, old behavior could be restored using the new flag --watch-all #5310

Other enhancements:

  • stack ls dependencies json now includes fields sha256 and size for dependencies of type archive in location. #5280
  • Build failures now show a hint to scroll up to the corresponding section #5279
  • Customisable output styles (see stack --help and the --stack-colors option, and stack ls stack-colors --help) now include info, debug, other-level, secondary and highlight, used with verbose output.

Bug fixes:

  • Fix stack test --coverage when using Cabal 3
  • stack new now generates PascalCase’d module name correctly. #5376
  • Connection issues to Casa server no longer cause builds to failure. Casa acts only as an optimizing cache layer, not a critical piece of infrastructure.
  • Fix modified time busting caches by always calculating sha256 digest during the build process. #5125


Changes since v2.3.1

Other enhancements:

  • Add the stack-developer-mode flag

Bug fixes:

  • When using the STACK_YAML env var with Docker, make the path absolute.
  • Fix the problem of stack repl foo:test:bar failing without a project build before that. See #5213
  • Fix stack sdist introducing unnecessary sublibrary syntax when using pvp-bounds. See #5289


Release notes:

  • We have reduced the number of platforms that we support with binary releases. The reason behind this is that we’ve been slowed down in our release process until now with issues trying to build binaries for less common platforms. In order to make sure we can address issues more quickly (like supporting new GHC versions), we’re limiting support from the Stack team to:

    • Linux 64-bit (static)
    • macOS
    • Windows 64-bit

    If others want to provide additional binaries, we will definitely be happy for the support. But since our CI system is currently able to produce these three bindists only, that’s what we will be providing with the next release.

  • Since we no longer have dynamically linked Linux binaries, we are removing removing the -static suffix from the static Linux binaries. If you have scripts to download the latest stable Linux binary, update them to use linux-x86_64 instead of linux-x86_64-static (if you are already using the former, nothing needs to change). For this release, both are supported, but the next release will no longer have the -static variant.

  • We are also deprecating the download links at See this page for the current installation instructions:

  • These are the canonical locations to download the latest stable binaries from, and will continue to be supported going forward:

    As always, binaries for specific versions are available from the GitHub releases:

Changes since v2.1.3.1

Major changes:

  • setup-info-locations yaml configuration now allows overwriting the default locations of stack-setup-2.yaml. #5031 #2983 #2913

  • The setup-info configuration key now allows overwriting parts of the default setup-info

  • The --setup-info-yaml command line flag now may be used in all Stack commands such as stack build, and not only in stack setup

  • The --setup-info-yaml may specify multiple locations for stack-setup.yaml files.

  • The stack upload can read first reads environment Variable $HACKAGE_USERNAME and $HACKAGE_PASSWORD if they are missing only then asks for username or password

  • Fully remove GHCJS support.

  • Remove the freeze command. It has been replaced by lock files.

Behavior changes:

  • Remove the deprecated --stack-setup-yaml command line argument in favor of --setup-info-yaml. See #2647

  • We now recommend checking in generated Cabal files for repos. When generating lock files for extra-deps that only include package.yaml files, a deprecation warning will be generated. Also, those packages will no longer be included in the generated lock files. See #5210.

Other enhancements:

  • Add build-output-timestamps flag in yaml. Setting it to true prefixes each build log output line with a timestamp.

  • Show warning about local-programs-path with spaces on windows when running scripts. See #5013

  • Add ls dependencies json which will print dependencies as JSON. ls dependencies --tree is now ls dependencies tree. See #4424

  • Remove warning for using Stack with GHC 8.8-8.10, and Cabal 3.0-3.2.

  • Allow relative paths in --setup-info-yaml and tool paths #3394

  • Added the --only-locals flag. See #5272

Bug fixes:

  • Upgrade pantry: module mapping insertions into the database are now atomic. Previously, if you SIGTERMed at the wrong time while running a script, you could end up with an inconsistent database state.

  • --resolver global doesn’t retrieve snapshots list from the internet because doesn’t need it. See #5103

  • Fix using relative links in haddocks output. See #4971.

  • Do not include generated Cabal file information in lock files. See #5045.

  • Use proper Hoogle executable path when installed automatically. See #4905

  • Fix GHC version for batched package unregistration. See #4951

  • Use Hoogle from the snapshot used and not the latest version. See #4905

  • Resolve “‘stty’ is not recognized”. See #4901

  • Fix missing reconfigure check causing errors when a package gets used in multiple projects. See #5147


Hackage-only release:

  • Support persistent-template-2.7.x
  • Support rio-
  • Add stack.yaml back to hackage sdist, and add snapshot.yaml


Changes since v2.1.1

Behavior changes:

  • Disable WAL mode for SQLite3 databases, to improve compatibility with some platforms and filesystems. See #4876.

  • By default, do not perform expiry checks in Hackage Security. See #4928.

Other enhancements:

  • Do not rerun expected test failures. This is mostly a change that will only affect the Stackage Curator use case, but there is now an additional message letting the user know when a previously-failed test case is being rerun.

  • Move configure information for local packages back to .stack-work to improve caching. See #4893.

Bug fixes:

  • Fix to allow dependencies on specific versions of local git repositories. See #4862

  • Allow Stack commands to be run in Nix mode without having a project file available. See #4854.

  • Removes dependency on gnu-tar for OSX and Linux environment. The --force-local option was required only for windows environment.

  • Properly wait for the tar subprocess to complete before returning, thereby avoiding a SIGTERM screwing up GHC installation. See #4888.

  • Use package complete locations from lock files when resolving dependencies in extra-deps. See #4887.

  • Set the HASKELL_DIST_DIR environment to a proper package dist directory so doctest is able to load modules autogenerated by Cabal.

  • Expose package library when running tests.

  • Fix support for non-ASCII module names. See #4938

Other changes:

  • Rename pantry-tmp package back to pantry, now that we have gained maintainership (which had been used by someone else for a candidate-only test that made it look like the name was free but prevented uploading a real package).


Hackage-only release that removes stack.yaml from the sdist. This is because stack.yaml now defines a multi-package project, whereas Hackage works on the basis on individual packages (see #4860)

If building a stack executable for distribution, please download the source code from and build it using Stack itself in order to ensure identical behaviour to official binaries. This package on Hackage is provided for convenience and bootstrapping purposes.


The Stack 2 release represents a series of significant changes to how Stack works internally. For the vast majority of cases, these changes are backwards compatible, in that existing projects will continue to build in the same way with Stack 2 as they did with Stack 1. The large version bump is due to the fundamental internal changes to cache handling, database storage (using SQLite in place of binary files), implicit snapshots (which greatly improve the precompiled cache), and moving to Pantry. We have also removed some less used features, as listed below.

Changes since v1.9.3

Major changes:

  • Switch over to pantry for managing packages. This is a major change to Stack’s internals, and affects user-visible behavior in a few places. Some highlights:
    • Drop support for multiple package indices and legacy 00-index.tar style indices. See #4137.
    • Support for archives and repos in the packages section has been removed. Instead, you must use extra-deps for such dependencies. packages now only supports local filepaths.
    • Add support for Git repositories containing (recursive) submodules.
    • Addition of new configuration options for specifying a “pantry tree” key, which provides more reproducibility around builds, and (in the future) will be used for more efficient package content downloads. You can also specify package name and version for more efficient config parsing. * NOTE The new stack freeze command provides support for automatically generating this additional information.
    • Package contents and metadata are stored in an SQLite database in place of files on the filesystem. The pantry library can be used for interacting with these contents.
    • Internally, Stack has changed many datatypes, including moving to Cabal’s definition of many data types. As a result of such changes, existing cache files will in general be invalidated, resulting in Stack needing to rebuild many previously cached builds in the new version. Sorry :(.
    • A new command, stack freeze has been added which outputs project and snapshot definitions with dependencies pinned to their exact versions.
    • The ignore-revision-mismatch setting is no longer needed, and has been removed.
    • Overriding GHC boot packages results in any other GHC boot packages depending on it being no longer available as a dependency, such packages need to be added explicitly when needed. See [#4510] (
    • Cabal solver integration was not updated to support newer cabal-install versions so stack solver command was removed as well as a related option --solver from stack new and stack init.
  • Upgrade to Cabal 2.4
    • Note that, in this process, the behavior of file globbing has been modified to match that of Cabal. In particular, this means that for Cabal spec versions less than 2.4, *.txt will match foo.txt, but not foo.2.txt.
  • Remove the stack image command. With the advent of Docker multistage builds, this functionality is no longer useful. For an example, please see Building Haskell Apps with Docker.
  • Support building GHC from source (experimental)
    • Stack now supports building and installing GHC from source. The built GHC is uniquely identified by a commit id and an Hadrian “flavour” (Hadrian is the newer GHC build system), hence compiler can be set to use a GHC built from source with ghc-git-COMMIT-FLAVOUR
  • stack.yaml now supports a configure-options, which are passed directly to the configure step in the Cabal build process. See #1438
  • Remove support for building GHCJS itself. Future releases of Stack may remove GHCJS support entirely.
  • Support for lock files for pinning exact project dependency versions

Behavior changes:

  • stack.yaml now supports snapshot: a synonym for resolver. See #4256
  • stack script now passes -i -idir in to the ghc invocation. This makes it so that the script can import local modules, and fixes an issue where .hs files in the current directory could affect interpretation of the script. See #4538
  • When using stack script, custom snapshot files will be resolved relative to the directory containing the script.
  • Remove the deprecated --upgrade-cabal flag to stack setup.
  • Support the drop-packages field in stack.yaml
  • Remove the GPG signing code during uploads. The GPG signatures have never been used yet, and there are no plans to implement signature verification.
  • Remove the --plain option for the exec family of commands
  • Always use the --exact-configuration Cabal configuration option when building (should mostly be a non-user-visible enhancement).
  • No longer supports Cabal versions older than 1.19.2. This means projects using snapshots earlier than lts-3.0 or nightly-2015-05-05 will no longer build.
  • Remove the stack docker cleanup command. Docker itself now has docker image prune and docker container prune, which you can use instead.
  • Interleaved output is now turned on by default, see #4702. In addition, the packagename> prefix is no longer included in interleaved mode when only building a single target.
  • The -fhide-source-paths GHC option is now enabled by default and can be disabled via the hide-source-paths configuration option in stack.yaml. See #3784
  • Stack will reconfigure a package if you modify your PATH environment variable. See #3138.
  • For GHC 8.4 and later, disable the “shadowed dependencies” workaround. This means that Stack will no longer have to force reconfigures as often. See #3554.
  • When building a package, Stack takes a lock on the dist directory in use to avoid multiple runs of Stack from trampling each others’ files. See #2730.
  • Stack will check occasionally if there is a new version available and prompt the user to upgrade. This will not incur any additional network traffic, as it will piggy-back on the existing Hackage index updates. You can set recommend-stack-upgrade: false to bypass this. See #1681.
  • stack list-dependencies has been removed in favour of stack ls dependencies.
  • The new default for --docker-auto-pull is enabled. See #3332.

Other enhancements:

  • Support MX Linux in Fixes #4769.
  • Defer loading up of files for local packages. This allows us to get plan construction errors much faster, and avoid some unnecessary work when only building a subset of packages. This is especially useful for the curator use case.
  • Existing global option --color=WHEN is now also available as a non-project-specific yaml configuration parameter color:.
  • Adopt the standard proposed at, that color should not be added by default if the NO_COLOR environment variable is present.
  • New command stack ls stack-colors lists the styles and the associated ‘ANSI’ control character sequences that Stack uses to color some of its output. See stack ls stack-colors --help for more information.
  • New global option --stack-colors=STYLES, also available as a non-project-specific yaml configuration parameter, allows a Stack user to redefine the default styles that Stack uses to color some of its output. See stack --help for more information.
  • British English spelling of ‘color’ (colour) accepted as an alias for --color, --stack-colors, stack ls stack-colors at the command line and for color: and stack-colors: in yaml configuration files.
  • New build option --ddump-dir. (See #4225)
  • Stack parses and respects the preferred-versions information from Hackage for choosing latest version of a package in some cases, e.g. stack unpack packagename.
  • The components output in the The main module to load is ambiguous message now include package names so they can be more easily copy-pasted.
  • Git repos are shared across multiple projects. See #3551
  • Use en_US.UTF-8 locale by default in pure Nix mode so programs won’t crash because of Unicode in their output #4095
  • Add --tree to ls dependencies to list dependencies as tree. #4101
  • Add --pedantic to ghci to run with -Wall and -Werror #4463
  • Add --cabal-files flag to stack ide targets command.
  • Add --stdout flag to all stack ide subcommands.
  • Use batches when unregistering packages with ghc-pkg. (See #2662)
  • get-stack script now works on Windows CI machines of Appveyor, Travis and Azure Pipelines. See #4535/
  • Show snapshot being used when stack ghci is invoked outside of a project directory. See #3651
  • The script interpreter now accepts a --extra-dep flag for adding packages not present in the snapshot. Currently, this only works with packages from Hackage, not Git repos or archives.
  • When using the script interpreter with --optimize or --compile, Stack will perform an optimization of checking whether a newer executable exists, making reruns significantly faster. There’s a downside to this, however: if you have a multifile script, and change one of the dependency modules, Stack will not automatically detect and recompile.
  • stack clean will delete the entire .stack-work/dist directory, not just the relevant subdirectory for the current GHC version. See #4480.
  • Add stack purge as a shortcut for stack clean --full. See #3863.
  • Both stack dot and stack ls dependencies accept a --global-hints flag to bypass the need for an installed GHC. See #4390.
  • Add the stack config env command for getting shell script environment variables. See #620.
  • Less verbose output from stack setup on Windows. See #1212.
  • Add an optional ignore-expiry flag to the hackage-security section of the ~/.stack/config.yaml. It allows to disable timestamp expiration verification just like cabal --ignore-expiry does. The flag is not enabled by default so that the default functionality is not changed.
  • Include default values for most command line flags in the --help output. See #893.
  • Set the GHC_ENVIRONMENT environment variable to specify dependency packages explicitly when running test. This is done to prevent ambiguous module name errors in doctest tests.
  • get-stack script now works on Windows CI machines of Appveyor, Travis and Azure Pipelines. See #4535
  • Warn when a Docker image does not include a PATH environment variable. See #2472
  • When using system-ghc: true, Stack will now find the appropriate GHC installation based on the version suffix, allowing you to more easily switch between various system-installed GHCs. See #2433.
  • stack init will now support create a stack.yaml file without any local packages. See #2465
  • Store caches in SQLite database instead of files.
  • No longer use “global” Docker image database (docker.db).
  • User config files are respected for the script command. See #3705, #3887.
  • Set the GHC_ENVIRONMENT environment variable to - to tell GHC to ignore any such files when GHC is new enough (>= 8.4.4), otherwise simply unset the variable. This allows Stack to have control of package databases when running commands like stack exec ghci, even in the presence of implicit environment files created by cabal new-build. See #4706.
  • Use a database cache table to speed up discovery of installed GHCs
  • You can specify multiple --test-arguments options. See #2226
  • Windows terminal width detection is now done. See #3588
  • On Windows, informs users if the ‘programs’ path contains a space character and further warns users if that path does not have an alternative short (‘8 dot 3’) name, referencing the local-programs-path configuration option. See #4726
  • Add --docker-mount-mode option to set the Docker volume mount mode for performance tuning on macOS.

Bug fixes:

  • Ignore duplicate files for a single module when a Haskell module was generated from a preprocessor file. See #4076.
  • Only track down components in current directory if there are no hs-source-dirs found. This eliminates a number of false-positive warnings, similar to #4076.
  • Handle a change in GHC’s hi-dump format around addDependentFile, which now includes a hash. See yesodweb/yesod#1551
  • Fix subdirs for git repos in extra-deps to match whole directory names. Also fixes for subdirs: .. See #4292
  • Fix for git packages to update submodules to the correct state. See #4314
  • Add --cabal-files flag to stack ide targets command.
  • Don’t download ghc when using stack clean.
  • Support loading in GHCi definitions from symlinked C files. Without this patch, Stack will try to find object files in the directory pointed to by symlinks, while GCC will produce the object files in the original directory. See #4402
  • Fix handling of GitHub and URL templates on Windows. See #4394
  • Fix --file-watch not responding to file modifications when running inside docker on Mac. See #4506
  • Using --ghc-options with stack script --compile now works.
  • Ensure the detailed-0.9 type tests work. See #4453.
  • Extra include and lib dirs are now order-dependent. See #4527.
  • Apply GHC options when building a Setup.hs file. See #4526.
  • Stack handles ABI changes in FreeBSD 12 by differentiating that version from previous.
  • Help text for the templates subcommand now reflects behaviour in Stack 1.9 — that it downloads and shows a help file, rather than listing available templates.
  • Fix detection of aarch64 platform (this broke when we upgraded to a newer Cabal version).
  • Docker: fix detecting and pulling missing images with --docker-auto-pull. See #4598
  • Hackage credentials are not world-readable. See #2159.
  • Warnings are dumped from logs even when color is enabled. See #2997
  • stack init will now work for Cabal files with sublibraries. See #4408
  • When the Cabal spec version is newer than the global Cabal version, build against the snapshot’s Cabal library. See #4488
  • Docker: fix detection of expected subprocess failures. This fixes downloading a compatible stack executable when the host stack is not compatible with the Docker image (on Linux), and doesn’t show an unnecessary extra error when the in-container re-exec’ed stack exits with failure.
  • The stack ghci command’s --ghc-options flag now parses multiple options. See #3315.


Hackage-only release with no user facing changes (added compatibility with rio-


Bug fixes:

  • Stack can now be compiled again inside a directory that does not contain a .git directory. See #4364
  • Handle a change in GHC’s hi-dump format around addDependentFile, which now includes a hash. See yesodweb/yesod#1551
  • Allow variables to appear in template file names.


Hackage-only release with no user facing changes.

  • Stack can now be compiled again inside a directory that does not contain a .git directory. See #4364


Release notes:

  • Statically linked Linux bindists are back again, thanks to @nh2.
  • We will be deleting the Ubuntu, Debian, CentOS, Fedora, and Arch package repos from soon. These have been deprecated for over a year and have not received new releases, but were left in place for compatibility with older scripts.

Major changes:

  • Upgrade to Cabal 2.4
    • Note that, in this process, the behavior of file globbing has been modified to match that of Cabal. In particular, this means that for Cabal spec versions less than 2.4, *.txt will match foo.txt, but not foo.2.txt.
  • GHCJS support is being downgraded to ‘experimental’. A warning notifying the user of the experimental status of GHCJS will be displayed.

Behavior changes:

  • ghc-options from stack.yaml are now appended to ghc-options from config.yaml, whereas before they would be replaced.
  • stack build will now announce when sublibraries of a package are being build, in the same way executables, tests, benchmarks and libraries are announced
  • stack sdist will now announce the destination of the generated tarball, regardless of whether or not it passed the sanity checks
  • The --upgrade-cabal option to stack setup has been deprecated. This feature no longer works with GHC 8.2 and later. Furthermore, the reason for this flag originally being implemented was drastically lessened once Stack started using the snapshot’s Cabal library for custom setups. See: #4070.
  • With the new namespaced template feature, stack templates is no longer able to meaningfully display a list of all templates available. Instead, the command will download and display a help file with more information on how to discover templates. See: #4039
  • Build tools are now handled in a similar way to cabal-install. In particular, for legacy build-tools fields, we use a hard-coded list of build tools in place of looking up build tool packages in a tool map. This both brings Stack’s behavior closer into line with cabal-install, avoids some bugs, and opens up some possible optimizations/laziness. See: #4125.
  • Mustache templating is not applied to large files (over 50kb) to avoid performance degradation. See: #4133.
  • stack upload signs the package by default, as documented. --no-signature turns the signing off. #3739
  • In case there is a network connectivity issue while trying to download a template, Stack will check whether that template had been downloaded before. In that case, the cached version will be used. See #3850.

Other enhancements:

  • On Windows before Windows 10, –color=never is the default on terminals that can support ANSI color codes in output only by emulation
  • On Windows, recognise a ‘mintty’ (false) terminal as a terminal, by default
  • stack build issues a warning when base is explicitly listed in extra-deps of stack.yaml
  • stack build suggests trying another GHC version should the build plan end up requiring unattainable base version.
  • A new sub command run has been introduced to build and run a specified executable similar to cabal run. If no executable is provided as the first argument, it defaults to the first available executable in the project.
  • stack build missing dependency suggestions (on failure to construct a valid build plan because of missing deps) are now printed with their latest Cabal file revision hash. See #4068.
  • Added new --tar-dir option to stack sdist, that allows to copy the resulting tarball to the specified directory.
  • Introduced the --interleaved-output command line option and build.interleaved-output config value which causes multiple concurrent builds to dump to stderr at the same time with a packagename> prefix. See #3225.
  • The default retry strategy has changed to exponential backoff. This should help with #3510.
  • stack new now allows template names of the form username/foo to download from a user other than commercialstack on GitHub, and can be prefixed with the service github:, gitlab:, or bitbucket:. See #4039
  • Switch to githash to include some unmerged bugfixes in gitrev Suggestion to add 'allow-newer': true now shows path to user config file where this flag should be put into #3685
  • stack ghci now asks which main target to load before doing the build, rather than after
  • Bump to Hpack 0.29.0
  • With GHC 8.4 and later, Haddock is given the --quickjump flag.
  • It is possible to specify the Hackage base URL to upload packages to, instead of the default of, by using hackage-base-url configuration option.
  • When using Nix, if a specific minor version of GHC is not requested, the latest minor version in the given major branch will be used automatically.

Bug fixes:

  • stack ghci now does not invalidate .o files on repeated runs, meaning any modules compiled with -fobject-code will be cached between ghci runs. See #4038.
  • ~/.stack/config.yaml and stack.yaml terminating by newline
  • The previous released caused a regression where some stderr from the ghc-pkg command showed up in the terminal. This output is now silenced.
  • A regression in recompilation checking introduced in v1.7.1 has been fixed. See #4001
  • stack ghci on a package with internal libraries was erroneously looking for a wrong package corresponding to the internal library and failing to load any module. This has been fixed now and changes to the code in the library and the sublibrary are properly tracked. See #3926.
  • For packages with internal libraries not depended upon, stack build used to fail the build process since the internal library was not built but it was tried to be registered. This is now fixed by always building internal libraries. See #3996.
  • --no-nix was not respected under NixOS
  • Fix a regression which might use a lot of RAM. See #4027.
  • Order of commandline arguments does not matter anymore. See #3959
  • When prompting users about saving their Hackage credentials on upload, flush to stdout before waiting for the response so the prompt actually displays. Also fixes a similar issue with ghci target selection prompt.
  • If cabal is not on PATH, running stack solver now prompts the user to run stack install cabal-install
  • stack build now succeeds in building packages which contain sublibraries which are dependencies of executables, tests or benchmarks but not of the main library. See #3787.
  • Sublibraries are now properly considered for coverage reports when the test suite depends on the internal library. Before, Stack was erroring when trying to generate the coverage report, see #4105.
  • Sublibraries are now added to the precompiled cache and recovered from there when the snapshot gets updated. Previously, updating the snapshot when there was a package with a sublibrary in the snapshot resulted in broken builds. This is now fixed, see #4071.
  • #4114 Stack pretty prints error messages with proper error logging level instead of warning now. This also fixes self-executing scripts not piping plan construction errors from runhaskell to terminal (issue #3942).
  • Fix invalid “While building Setup.hs” when Cabal calls fail. See: #3934
  • stack upload signs the package by default, as documented. --no-signature turns the signing off. #3739


Release notes:

  • aarch64 (64-bit ARM) bindists are now available for the first time.
  • Statically linked Linux bindists are no longer available, due to difficulty with GHC 8.2.2 on Alpine Linux.
  • 32-bit Linux GMP4 bindists for CentOS 6 are no longer available, since GHC 8.2.2 is no longer being built for that platform.

Major changes:

  • Upgrade from Cabal 2.0 to Cabal 2.2

Behavior changes:

  • stack setup no longer uses different GHC configure options on Linux distributions that use GCC with PIE enabled by default. GHC detects this itself since ghc-8.0.2, and Stack’s attempted workaround for older versions caused more problems than it solved.
  • stack new no longer initializes a project if the project template contains a stack.yaml file.

Other enhancements:

  • A new sub command ls has been introduced to Stack to view local and remote snapshots present in the system. Use stack ls snapshots --help to get more details about it.
  • list-dependencies has been deprecated. The functionality has to accessed through the new ls dependencies interface. See #3669 for details.
  • Specify User-Agent HTTP request header on every HTTP request. See #3628 for details.
  • stack setup looks for GHC bindists and installations by any OS key that is compatible (rather than only checking a single one). This is relevant on Linux where different distributions may have different combinations of libtinfo 5/6, ncurses 5/6, and gmp 4/5, and will allow simplifying the setup-info metadata YAML for future GHC releases.
  • The build progress bar reports names of packages currently building.
  • stack setup --verbose causes verbose output of GHC configure process. See #3716
  • Improve the error message when an extra-dep from a path or git reference can’t be found. See #3808
  • Nix integration is now disabled on windows even if explicitly enabled, since it isn’t supported. See #3600
  • stack build now supports a new flag --keep-tmp-files to retain intermediate files and directories for the purpose of debugging. It is best used with ghc’s equivalent flag, i.e. stack build --keep-tmp-files --ghc-options=-keep-tmp-files. See #3857
  • Improved error messages for snapshot parse exceptions
  • stack unpack now supports a --to /target/directory option to specify where to unpack the package into
  • stack hoogle now supports a new flag --server that launches local Hoogle server on port 8080. See #2310

Bug fixes:

  • The script interpreter’s implicit file arguments are now passed before other arguments. See #3658. In particular, this makes it possible to pass -- +RTS ... -RTS to specify RTS arguments used when running the script.
  • Don’t ignore the template year parameter in config files, and clarify the surrounding documentation. See #2275.
  • Benchmarks used to be run concurrently with other benchmarks and build steps. This is non-ideal because CPU usage of other processes may interfere with benchmarks. It also prevented benchmark output from being displayed by default. This is now fixed. See #3663.
  • stack ghci now allows loading multiple packages with the same module name, as long as they have the same filepath. See #3776.
  • stack ghci no longer always adds a dependency on base. It is now only added when there are no local targets. This allows it to be to load code that uses replacements for base. See #3589
  • stack ghci now uses correct paths for autogen files with #3791
  • When a package contained sublibraries, Stack was always recompiling the package. This has been fixed now, no recompilation is being done because of sublibraries. See #3899.
  • The install script now matches manual instructions when it comes to Debian/Fedora/CentOS install dependencies.
  • Compile Cabal-simple with gmp when using Nix. See #2944
  • stack ghci now replaces the Stack process with ghci. This improves signal handling behavior. In particular, handling of Ctrl-C. To make this possible, the generated files are now left behind after exit. The paths are based on hashing file contents, and it’s stored in the system temporary directory, so this shouldn’t result in too much garbage. See #3821.


Bug fixes:

  • Some unnecessary rebuilds when no files were changed are now avoided, by having a separate build cache for each component of a package. See #3732.
  • Correct the behavior of promoting a package from snapshot to local package. This would get triggered when version bounds conflicted in a snapshot, which could be triggered via Hackage revisions for old packages. This also should allow custom snapshots to define conflicting versions of packages without issue. See Stackage issue #3185.
  • When promoting packages from snapshot to local, we were occasionally discarding the actual package location content and instead defaulting to pulling the package from the index. We now correctly retain this information. Note that if you were affected by this bug, you will likely need to delete the binary build cache associated with the relevant custom snapshot. See #3714.
  • --no-rerun-tests has been fixed. Previously, after running a test we were forgetting to record the result, which meant that all tests always ran even if they had already passed before. See #3770.
  • Includes a patched version of hackage-security which fixes both some issues around asynchronous exception handling, and moves from directory locking to file locking, making the update mechanism resilient against SIGKILL and machine failure. See hackage-security issue #187 and Stack issue #3073.


Hackage-only release with no user facing changes (updated to build with newer version of Hpack dependency).



  • In addition to supporting .tar.gz and .zip files as remote archives, plain .tar files are now accepted too. This will additionally help with cases where HTTP servers mistakenly set the transfer encoding to gzip. See #3647.
  • Links to ignore Stack version patchlevel.
  • Downloading Docker-compatible stack binary ignores Stack version patchlevel.

Bug fixes:

  • For versions of Cabal before 1.24, ensure that the dependencies of non-buildable components are part of the build plan to work around an old Cabal bug. See #3631.
  • Run the Cabal file checking in the sdist command more reliably by allowing the Cabal library to flatten the GenericPackageDescription itself.


Hackage-only release with no user facing changes (updated to build with newer dependency versions).


Major changes:

  • Complete overhaul of how snapshots are defined, the packages and extra-deps fields, and a number of related items. For full details, please see the writeup on these changes. PR #3249, see the PR description for a number of related issues.
  • Upgraded to version 2.0 of the Cabal library.

Behavior changes:

  • The --install-ghc flag is now on by default. For example, if you run stack build in a directory requiring a GHC that you do not currently have, Stack will automatically download and install that GHC. You can explicitly set install-ghc: false or pass the flag --no-install-ghc to regain the previous behavior.
  • stack ghci no longer loads modules grouped by package. This is always an improvement for plain ghci - it makes loading faster and less noisy. For intero, this has the side-effect that it will no longer load multiple packages that depend on TH loading relative paths. TH relative paths will still work when loading a single package into intero. See #3309
  • Setting GHC options for a package via ghc-options: in your stack.yaml will promote it to a local package, providing for more consistency with flags and better reproducibility. See: #849
  • The package-indices setting with Hackage no longer works with the 00-index.tar.gz tarball, but must use the 01-index.tar.gz file to allow revised packages to be found.
  • Options passed via --ghci-options are now passed to the end of the invocation of ghci, instead of the middle. This allows using +RTS without an accompanying -RTS.
  • When auto-detecting --ghc-build, tinfo6 is now preferred over standard if both versions of libtinfo are installed
  • Addition of stack build --copy-compiler-tool, to allow tools like intero to be installed globally for a particular compiler. #2643
  • Stack will ask before saving hackage credentials to file. This new prompt can be avoided by using the save-hackage-creds setting. Please see #2159.
  • The GHCRTS environment variable will no longer be passed through to every program Stack runs. Instead, it will only be passed through commands like exec, runghc, script, ghci, etc. See #3444.
  • ghc-options: for specific packages will now come after the options specified for all packages / particular sets of packages. See #3573.
  • The pvp-bounds feature is no longer fully functional, due to some issues with the Cabal library’s printer. See #3550.

Other enhancements:

  • The with-hpack configuration option specifies an Hpack executable to use instead of the Hpack bundled with Stack. Please see #3179.
  • It’s now possible to skip tests and benchmarks using --skip flag
  • GitSHA1 is now StaticSHA256 and is implemented using the StaticSize 64 ByteString for improved performance. See #3006
  • Dependencies via HTTP(S) archives have been generalized to allow local file path archives, as well as to support setting a cryptographic hash (SHA256) of the contents for better reproducibility.
  • Allow specifying --git-branch when upgrading
  • When running stack upgrade from a file which is different from the default executable path (e.g., on POSIX systems, ~/.local/bin/stack), it will now additionally copy the new executable over the currently running stack executable. If permission is denied (such as in /usr/local/bin/stack), the user will be prompted to try again using sudo. This is intended to assist with the user experience when the PATH environment variable has not been properly configured, see #3232.
  • stack setup for ghcjs will now install alex and happy if they are not present. See #3109.
  • Added stack ghci --only-main flag, to skip loading / importing all but main modules. See the ghci documentation page for further info.
  • Allow GHC’s colored output to show through. GHC colors output starting with version 8.2.1, for older GHC this does nothing. Sometimes GHC’s heuristics would work fine even before this change, for example in stack ghci, but this override’s GHC’s heuristics when they’re broken by our collecting and processing GHC’s output.
  • Extended the ghc-options field to support $locals, $targets, and $everything. See: #3329
  • Better error message for case that stack ghci file targets are combined with invalid package targets. See: #3342
  • For profiling now uses -fprof-auto -fprof-cafs instead of the deprecated -auto-all -caf-all. See: #3360
  • Better descriptions are now available for stack upgrade --help. See: #3070
  • When using Nix, nix-shell now depends always on gcc to prevent build errors when using the FFI. As ghc depends on gcc anyway, this doesn’t increase the dependency footprint.
  • --cwd DIR can now be passed to stack exec in order to execute the program in a different directory. See: #3264
  • Plan construction will detect if you add an executable-only package as a library dependency, resulting in much clearer error messages. See: #2195.
  • Addition of --ghc-options to stack script to pass options directly to GHC. See: #3454
  • Add Hpack package.yaml to build Stack itself
  • Add ignore-revision-mismatch setting. See: #3520.
  • Log when each individual test suite finishes. See: #3552.
  • Avoid spurious rebuilds when using --file-watch by not watching files for executable, test and benchmark components that aren’t a target. See: #3483.
  • Stack will now try to detect the width of the running terminal (only on POSIX for the moment) and use that to better display output messages. Work is ongoing, so some messages will not be optimal yet. The terminal width can be overridden with the new --terminal-width command-line option (this works even on non-POSIX).
  • Passing non local packages as targets to stack ghci will now cause them to be used as -package args along with package hiding.
  • Detect when user changed Cabal file instead of package.yaml. This was implemented upstream in Hpack. See #3383.
  • Automatically run autoreconf -i as necessary when a configure script is missing. See #3534
  • GHC bindists can now be identified by their SHA256 checksum in addition to their SHA1 checksum, allowing for more security in download.
  • For filesystem setup-info paths, it’s no longer assumed that the directory is writable, instead a temp dir is used. See #3188.

Bug fixes:

  • stack hoogle correctly generates Hoogle databases. See: #3362
  • stack --docker-help is now clearer about –docker implying system-ghc: true, rather than both –docker and –no-docker.
  • stack haddock now includes package names for all modules in the Haddock index page. See: #2886
  • Fixed an issue where Stack wouldn’t detect missing Docker images properly with newer Docker versions. #3171
  • Previously, Cabal files with just test-suite could cause build to fail (#2862)
  • If an invalid snapshot file has been detected (usually due to mismatched hashes), Stack will delete the downloaded file and recommend either retrying or filing an issue upstream. See #3319.
  • Modified the flag parser within Stack to match the behavior of Cabal’s flag parser, which allows multiple sequential dashes. See #3345
  • Now clears the hackage index cache if it is older than the downloaded index. Fixes potential issue if Stack was interrupted when updating index. See #3033
  • The Stack install script now respects the -d option. See #3366.
  • stack script can now handle relative paths to source files. See #3372.
  • Fixes explanation of why a target is needed by the build plan, when the target is an extra dependency from the commandline. See #3378.
  • Previously, if you delete a yaml file from ~/.stack/build-plan, it would trust the etag and not re-download. Fixed in this version.
  • Invoking stack --docker in parallel now correctly locks the sqlite database. See #3400.
  • RTD documentation search is replaced by the mkdocs search. Please see #3376.
  • stack clean now works with nix. See #3468.
  • stack build --only-dependencies no longer builds local project packages that are depended on. See #3476.
  • Properly handle relative paths stored in the precompiled cache files. See #3431.
  • In some cases, Cabal does not realize that it needs to reconfigure, and must be told to do so automatically. This would manifest as a “shadowed dependency” error message. We now force a reconfigure whenever a dependency is built, even if the package ID remained the same. See #2781.
  • When --pvp-bounds is enabled for sdist or upload, internal dependencies could cause errors when uploaded to hackage. This is fixed, see #3290
  • Fixes a bug where nonexistent hackage versions would cause Stack to suggest the same package name, without giving version info. See #3562
  • Fixes a bug that has existed since 1.5.0, where stack setup --upgrade-cabal would say that Cabal is already the latest version, when it wasn’t.
  • Ensure that an extra-dep from a local directory is not treated as a $locals for GHC options purposes. See #3574.
  • Building all executables only happens once instead of every time. See #3229 for more info.


Bug fixes:

  • Stack eagerly tries to parse all Cabal files related to a snapshot. Starting with Stackage Nightly 2017-07-31, snapshots are using GHC 8.2.1, and the ghc.cabal file implicitly referenced uses the (not yet supported) Cabal 2.0 file format. Future releases of Stack will both be less eager about Cabal file parsing and support Cabal 2.0. This patch simply bypasses the error for invalid parsing.


Behavior changes:

  • stack profile and stack trace now add their extra RTS arguments for benchmarks and tests to the beginning of the args, instead of the end. See #2399
  • Support for Git-based indices has been removed.

Other enhancements:

  • stack setup allow to control options passed to ghcjs-boot with --ghcjs-boot-options (one word at a time) and --[no-]ghcjs-boot-clean
  • stack setup now accepts a --install-cabal VERSION option which will install a specific version of the Cabal library globally.
  • Updates to store-0.4.1, which has improved performance and better error reporting for version tags. A side-effect of this is that all of stack’s binary caches will be invalidated.
  • stack solver will now warn about unexpected cabal-install versions. See #3044
  • Upstream packages unpacked to a temp dir are now deleted as soon as possible to avoid running out of space in /tmp. See #3018
  • Add short synonyms for test-arguments and benchmark-arguments options.
  • Adds STACK_WORK environment variable, to specify work dir. See #3063
  • Can now use relative paths for extra-include-dirs and extra-lib-dirs. See #2830
  • Improved bash completion for many options, including --ghc-options, --flag, targets, and project executables for exec.
  • --haddock-arguments is actually used now when haddock is invoked during documentation generation.
  • --[no-]haddock-hyperlink-source flag added which allows toggling of sources being included in Haddock output. See #3099
  • stack ghci will now skip building all local targets, even if they have downstream deps, as long as it’s registered in the DB.
  • The pvp-bounds feature now supports adding -revision to the end of each value, e.g. pvp-bounds: both-revision. This means that, when uploading to Hackage, Stack will first upload your tarball with an unmodified Cabal file, and then upload a Cabal file revision with the PVP bounds added. This can be useful - especially combined with the Stackage no-revisions feature - as a method to ensure PVP compliance without having to proactively fix bounds issues for Stackage maintenance.
  • Expose a save-hackage-creds configuration option
  • On GHC <= 7.8, filters out spurious linker warnings on windows See #3127
  • Better error messages when creating or building packages which alias wired-in packages. See #3172.
  • MinGW bin folder now is searched for dynamic libraries. See #3126
  • When using Nix, nix-shell now depends always on git to prevent runtime errors while fetching metadata
  • The stack unpack command now accepts a form where an explicit Hackage revision hash is specified, e.g. stack unpack foo-1.2.3@gitsha1:deadbeef. Note that this should be considered experimental, Stack will likely move towards a different hash format in the future.
  • Binary “stack upgrade” will now warn if the installed executable is not on the PATH or shadowed by another entry.
  • Allow running tests on tarball created by sdist and upload #717.

Bug fixes:

  • Fixes case where stack build --profile might not cause executables / tests / benchmarks to be rebuilt. See #2984
  • stack ghci file.hs now loads the file even if it isn’t part of your project.
  • stack clean --full now works when docker is enabled. See #2010
  • Fixes an issue where cyclic deps can cause benchmarks or tests to be run before they are built. See #2153
  • Fixes stack build --file-watch in cases where a directory is removed See #1838
  • Fixes stack dot and stack list-dependencies to use info from the package database for wired-in-packages (ghc, base, etc). See #3084
  • Fixes stack --docker build when user is part of libvirt/libvirtd groups on Ubuntu Yakkety (16.10). See #3092
  • Switching a package between extra-dep and local package now forces rebuild (previously it wouldn’t if versions were the same). See #2147
  • stack upload no longer reveals your password when you type it on MinTTY-based Windows shells, such as Cygwin and MSYS2. See #3142
  • stack script’s import parser will now properly parse files that have Windows-style line endings (CRLF)


Release notes:

Major changes:

  • A new command, script, has been added, intended to make the script interpreter workflow more reliable, easier to use, and more efficient. This command forces the user to provide a --resolver value, ignores all config files for more reproducible results, and optimizes the existing package check to make the common case of all packages already being present much faster. This mode does require that all packages be present in a snapshot, however. #2805

Behavior changes:

  • The default package metadata backend has been changed from Git to the 01-index.tar.gz file, from the hackage-security project. This is intended to address some download speed issues from GitHub for people in certain geographic regions. There is now full support for checking out specific Cabal file revisions from downloaded tarballs as well. If you manually specify a package index with only a Git URL, Git will still be used. See #2780

  • When you provide the --resolver argument to the stack unpack command, any packages passed in by name only will be looked up in the given snapshot instead of taking the latest version. For example, stack --resolver lts-7.14 unpack mtl will get version 2.2.1 of mtl, regardless of the latest version available in the package indices. This will also force the same Cabal file revision to be used as is specified in the snapshot.

    Unpacking via a package identifier (e.g. stack --resolver lts-7.14 unpack mtl-2.2.1) will ignore any settings in the snapshot and take the most recent revision.

    For backwards compatibility with tools relying on the presence of a 00-index.tar, Stack will copy the 01-index.tar file to 00-index.tar. Note, however, that these files are different; most importantly, 00-index contains only the newest revisions of Cabal files, while 01-index contains all versions. You may still need to update your tooling.

  • Passing --(no-)nix-* options now no longer implies --nix, except for --nix-pure, so that the user preference whether or not to use Nix is honored even in the presence of options that change the Nix behavior.

Other enhancements:

  • Internal cleanup: configuration types are now based much more on lenses
  • stack build and related commands now allow the user to disable debug symbol stripping with new --no-strip, --no-library-stripping, and --no-executable-shipping flags, closing #877. Also turned error message for missing targets more readable (#2384)
  • stack haddock now shows index.html paths when documentation is already up to date. Resolved #781
  • Respects the custom-setup field introduced in Cabal 1.24. This supercedes any explicit-setup-deps settings in your stack.yaml and trusts the package’s Cabal file to explicitly state all its dependencies.
  • If system package installation fails, will fail as well. Also shows warning suggesting to run apt-get update or similar, depending on the OS. (#2898)
  • When stack ghci is run with a config with no packages (e.g. global project), it will now look for source files in the current work dir. (#2878)
  • Bump to Hpack 0.17.0 to allow custom-setup and !include "..." in package.yaml.
  • The script interpreter will now output error logging. In particular, this means it will output info about plan construction errors. (#2879)
  • stack ghci now takes --flag and --ghc-options again (inadvertently removed in 1.3.0). (#2986)
  • stack exec now takes --rts-options which passes the given arguments inside of +RTS ... args .. -RTS to the executable. This works around Stack itself consuming the RTS flags on Windows. (#2640)
  • Upgraded http-client-tls version, which now offers support for the socks5:// and socks5h:// values in the http_proxy and https_proxy environment variables.

Bug fixes:

  • Bump to Hpack 0.16.0 to avoid character encoding issues when reading and writing on non-UTF8 systems.
  • stack ghci will no longer ignore hsSourceDirs that contain ... (#2895)
  • stack list-dependencies --license now works for wired-in-packages, like base. (#2871)
  • stack setup now correctly indicates when it uses system ghc (#2963)
  • Fix to stack config set, in 1.3.2 it always applied to the global project. (#2709)
  • Previously, Cabal files without exe or lib would fail on the “copy” step. (#2862)
  • stack upgrade --git now works properly. Workaround for affected versions (>= 1.3.0) is to instead run stack upgrade --git --source-only. (#2977)
  • Added support for GHC 8’s slightly different warning format for dumping warnings from logs.
  • Work around a bug in Cabal/GHC in which package IDs are not unique for different source code, leading to Stack not always rebuilding packages depending on local packages which have changed. (#2904)


Bug fixes:

  • stack config set can now be used without a compiler installed #2852.
  • now installs correct binary on ARM for generic linux and raspbian, closing #2856.
  • Correct the testing of whether a package database exists by checking for the package.cache file itself instead of the containing directory.
  • Revert a change in the previous release which made it impossible to set local extra-dep packages as targets. This was overkill; we really only wanted to disable their test suites, which was already handled by a later patch. #2849
  • stack new always treats templates as being UTF-8 encoding, ignoring locale settings on a local machine. See Yesod mailing list discussion


Release notes:

  • For the next Stack release after this one, we are planning changes to our Linux releases, including dropping our Ubuntu, Debian, CentOS, and Fedora package repositories and switching to statically linked binaries. See #2534. Note that upgrading without a package manager has gotten easier with new binary upgrade support in stack upgrade (see the Major Changes section below for more information). In addition, the script no longer installs from Ubuntu, Debian, CentOS, or Fedora package repositories. Instead it places a generic binary in /usr/local/bin.

Major changes:

  • Stack will now always use its own GHC installation, even when a suitable GHC installation is available on the PATH. To get the old behaviour, use the --system-ghc flag or run stack config set system-ghc --global true. Docker- and Nix-enabled projects continue to use the GHC installations in their environment by default.

    NB: Scripts that previously used Stack in combination with a system GHC installation should now include a stack setup line or use the --install-ghc flag. #2221

  • stack ghci now defaults to skipping the build of target packages, because support has been added for invoking “initial build steps”, which create autogen files and run preprocessors. The --no-build flag is now deprecated because it should no longer be necessary. See #1364

  • Stack is now capable of doing binary upgrades instead of always recompiling a new version from source. Running stack upgrade will now default to downloading a binary version of Stack from the most recent release, if one is available. See stack upgrade --help for more options. #1238

Behavior changes:

  • Passing --resolver X with a Stack command which forces creation of a global project config, will pass resolver X into the initial config. See #2579.

  • Switch the “Run from outside project” messages to debug-level, to avoid spamming users in the normal case of non-project usage

  • If a remote package is specified (such as a Git repo) without an explicit extra-dep setting, a warning is given to the user to provide one explicitly.

Other enhancements:

  • stack haddock now supports --haddock-internal. See #2229
  • Add support for system-ghc and install-ghc fields to stack config set command.
  • Add ghc-build option to override autodetected GHC build to use (e.g. gmp4, tinfo6, nopie) on Linux.
  • stack setup detects systems where gcc enables PIE by default (such as Ubuntu 16.10 and Hardened Gentoo) and adjusts the GHC configure options accordingly. #2542
  • Upload to Hackage with HTTP digest instead of HTTP basic.
  • Make stack list-dependencies understand all of the stack dot options too.
  • Add the ability for stack list-dependencies to list dependency licenses by passing the --license flag.
  • Dump logs that contain warnings for any local non-dependency packages #2545
  • Add the dump-logs config option and --dump-logs command line option to get full build output on the console. #426
  • Add the --open option to “stack hpc report” command, causing the report to be opened in the browser.
  • The stack config set command now accepts a --global flag for suitable fields which causes it to modify the global user configuration (~/.stack/config.yaml) instead of the project configuration. #2675
  • Information on the latest available snapshots is now downloaded from S3 instead of, increasing reliability in case of outages. #2653
  • stack dot and stack list-dependencies now take targets and flags. #1919
  • Deprecate stack setup --stack-setup-yaml for --setup-info-yaml based on discussion in #2647.
  • The --main-is flag for GHCI now implies the TARGET, fixing #1845.
  • stack ghci no longer takes all build options, as many weren’t useful #2199
  • --no-time-in-log option, to make verbose logs more diffable #2727
  • --color option added to override auto-detection of ANSI support #2725
  • Missing extra-deps are now warned about, adding a degree of typo detection #1521
  • No longer warns about missing build-tools if they are on the PATH. #2235
  • Replace enclosed-exceptions with safe-exceptions. #2768
  • The install location for GHC and other programs can now be configured with the local-programs-path option in config.yaml. #1644
  • Added option to add nix dependencies as nix GC roots
  • Proper pid 1 (init) process for stack exec with Docker
  • Dump build logs if they contain warnings. #2545
  • Docker: redirect stdout of docker pull to stderr so that it will not interfere with output of other commands.
  • Nix & docker can be activated at the same time, in order to run Stack in a nix-shell in a container, preferably from an image already containing the nix dependencies in its /nix/store
  • Stack/nix: Dependencies can be added as nix GC roots, so they are not removed when running nix-collect-garbage

Bug fixes:

  • Fixed a gnarly bug where programs and package tarballs sometimes have corrupted downloads. See #2657.
  • Add proper support for non-ASCII characters in file paths for the sdist command. See #2549
  • Never treat extra-dep local packages as targets. This ensures things like test suites are not run for these packages, and that build output is not hidden due to their presence.
  • Fix a resource leak in sinkProcessStderrStdout which could affect much of the codebase, in particular copying precompiled packages. #1979
  • Docker: ensure that interrupted extraction process does not cause corrupt file when downloading a Docker-compatible Stack executable #2568
  • Fixed running stack hpc report on package targets. #2664
  • Fix a long-standing performance regression where Stack would parse the .dump-hi files of the library components of local packages twice. #2658
  • Fixed a regression in “stack ghci –no-load”, where it would prompt for a main module to load. #2603
  • Build Setup.hs files with the threaded RTS, mirroring the behavior of cabal-install and enabling more complex build systems in those files.
  • Fixed a bug in passing along --ghc-options to ghcjs. They were being provided as --ghc-options to Cabal, when it needs to be --ghcjs-options. #2714
  • Launch Docker from the project root regardless of the working directory Stack is invoked from. This means paths relative to the project root (e.g. environment files) can be specified in stack.yaml’s docker run-args.
  • stack setup --reinstall now behaves as expected. #2554


Release notes:

  • On many Un*x systems, Stack can now be installed with a simple one-liner:

      wget -qO- | sh
  • The fix for #2175 entails that Stack must perform a full clone of a large Git repo of Hackage meta-information. The total download size is about 200 MB. Please be aware of this when upgrading your Stack installation.

  • If you use Mac OS X, you may want to delay upgrading to macOS Sierra as there are reports of GHC panics when building some packages (including Stack itself). See #2577

  • This version of Stack does not build on ARM or PowerPC systems (see store#37). Please stay with version 1.1.2 for now on those architectures. This will be rectified soon!

  • We are now releasing a statically linked Stack binary for 64-bit Linux. Please try it and let us know if you run into any trouble on your platform.

  • We are planning some changes to our Linux releases, including dropping our Ubuntu, Debian, CentOS, and Fedora package repositories and switching to statically linked binaries. We would value your feedback in #2534.

Major changes:

  • Add stack hoogle command. #55
  • Support for absolute file path in url field of setup-info or --ghc-bindist
  • Add support for rendering GHCi scripts targeting different GHCi like applications #2457

Behavior changes:

  • Remove stack ide start and stack ide load-targets commands. #2178
  • Support .buildinfo files in stack ghci. #2242
  • Support -ferror-spans syntax in GHC error messages.
  • Avoid unpacking ghc to /tmp #996
  • The Linux gmp4 GHC bindist is no longer considered a full-fledged GHC variant and can no longer be specified using the ghc-variant option, and instead is treated more like a slightly different platform.

Other enhancements:

  • Use the store package for binary serialization of most caches.
  • Only require minor version match for Docker Stack exe. This way, we can make patch releases for version bounds and similar build issues without needing to upload new binaries for Docker.
  • Stack/Nix: Passes the right ghc derivation as an argument to the shell.nix when a custom shell.nix is used. See #2243
  • Stack/Nix: Sets LD_LIBRARY_PATH so packages using C libs for Template Haskell can work (See e.g. this HaskellR issue)
  • Parse CLI arguments and configuration files into less permissive types, improving error messages for bad inputs. #2267
  • Add the ability to explicitly specify a gcc executable. #593
  • Nix: No longer uses LTS mirroring in nixpkgs. Gives to nix-shell a derivation like haskell.compiler.ghc801 See #2259
  • Perform some subprocesses during setup concurrently, slightly speeding up most commands. #2346
  • stack setup no longer unpacks to the system temp dir on posix systems. #996
  • stack setup detects libtinfo6 and ncurses6 and can download alternate GHC bindists #257 #2302.
  • stack setup detects Linux ARMv7 downloads appropriate GHC bindist #2103
  • Custom stack binaries list dependency versions in output for --version. See #2222 and #2450.
  • Use a pretty printer to output dependency resolution errors. #1912
  • Remove the --os flag #2227
  • Add ‘netbase’ and ‘ca-certificates’ as dependency for .deb packages. #2293.
  • Add stack ide targets command.
  • Enhance debug logging with subprocess timings.
  • Pretty-print YAML parse errors #2374
  • Clarify confusing stack setup output #2314
  • Delete Stack.Types multimodule to improve build times #2405
  • Remove spurious newlines in build logs #2418
  • Interpreter: Provide a way to hide implicit packages #1208
  • Check executability in exec lookup #2489

Bug fixes:

  • Fix Cabal warning about use of a deprecated Cabal flag #2350
  • Support most executable extensions on Windows #2225
  • Detect resolver change in stack solver #2252
  • Fix a bug in docker image creation where the wrong base image was selected #2376
  • Ignore special entries when unpacking tarballs #2361
  • Fixes src directory pollution of style.css and highlight.js with GHC 8’s haddock #2429
  • Handle filepaths with spaces in stack ghci #2266
  • Apply ghc-options to snapshot packages #2289
  • stack sdist: Fix timestamp in tarball #2394
  • Allow global Stack arguments with a script #2316
  • Inconsistency between ToJSON and FromJSON instances of PackageLocation #2412
  • Perform Unicode normalization on filepaths #1810
  • Solver: always keep ghc wired-in as hard constraints #2453
  • Support OpenBSD’s tar where possible, require GNU tar for xz support #2283
  • Fix using –coverage with Cabal-1.24 #2424
  • When marking exe installed, remove old version #2373
  • Stop truncating all-cabal-hashes git repo #2175
  • Handle non-ASCII filenames on Windows #2491
  • Avoid using multiple versions of a package in script interpreter by passing package-id to ghc/runghc #1957
  • Only pre-load compiler version when using nix integration #2459
  • Solver: parse Cabal errors also on Windows #2502
  • Allow exec and ghci commands in interpreter mode. Scripts can now automatically open in the repl by using exec ghci instead of runghc in the shebang command. #2510
  • Now consider a package to be dirty when an extra-source-file is changed. See #2040


Release notes:

Major changes:

  • Extensible custom snapshots implemented. These allow you to define snapshots which extend other snapshots. See #863. Local file custom snapshots can now be safely updated without changing their name. Remote custom snapshots should still be treated as immutable.

Behavior changes:

  • stack path --compiler was added in the last release, to yield a path to the compiler. Unfortunately, --compiler is a global option that is useful to use with stack path. The same functionality is now provided by stack path --compiler-exe. See #2123
  • For packages specified in terms of a git or hg repo, the hash used in the location has changed. This means that existing downloads from older stack versions won’t be used. This is a side-effect of the fix to #2133
  • stack upgrade no longer pays attention to local stack.yaml files, just the global config and CLI options. #1392
  • stack ghci now uses :add instead of :load, making it potentially work better with user scripts. See #1888

Other enhancements:

  • Grab Cabal files via Git SHA to avoid regressions from Hackage revisions #2070
  • Custom snapshots now support ghc-options.
  • Package git repos are now re-used rather than re-cloned. See #1620
  • DESTDIR is filtered from environment when installing GHC. See #1460
  • stack haddock now supports --haddock-arguments. See #2144
  • Signing: warn if GPG_TTY is not set as per man gpg-agent

Bug fixes:

  • Now ignore project config when doing stack init or stack new. See #2110
  • Packages specified by git repo can now have submodules. See #2133
  • Fix of hackage index fetch retry. See re-opening of #1418
  • HPack now picks up changes to filesystem other than package.yaml. See #2051
  • “stack solver” no longer suggests –omit-packages. See #2031
  • Fixed an issue with building Cabal’s Setup.hs. See #1356
  • Package dirtiness now pays attention to deleted files. See #1841
  • stack ghci now uses extra-lib-dirs and extra-include-dirs. See #1656
  • Relative paths outside of source dir added via qAddDependentFile are now checked for dirtiness. See #1982
  • Signing: always use --with-fingerprints


Release notes:

  • Added Ubuntu 16.04 LTS (xenial) Apt repo.
  • No longer uploading new versions to Fedora 21 repo.

Behavior changes:

  • Snapshot packages are no longer built with executable profiling. See #1179.
  • stack init now ignores symlinks when searching for Cabal files. It also now ignores any directory that begins with . (as well as dist dirs) - before it would only ignore .git, .stack-work, and dist.
  • The Stack executable is no longer built with -rtsopts. Before, when -rtsopts was enabled, Stack would process +RTS options even when intended for some other program, such as when used with stack exec -- prog +RTS. See #2022.
  • The stack path --ghc-paths option is deprecated and renamed to --programs. --compiler is added, which points directly at the compiler used in the current project. --compiler-bin points to the compiler’s bin dir.
  • For consistency with the $STACK_ROOT environment variable, the stack path --global-stack-root flag and the global-stack-root field in the output of stack path are being deprecated and replaced with the stack-root flag and output field. Additionally, the Stack root can now be specified via the --stack-root command-line flag. See #1148.
  • stack sig GPG-related sub-commands were removed (folded into upload and sdist)
  • GPG signing of packages while uploading to Hackage is now the default. Use upload --no-signature if you would rather not contribute your package signature. If you don’t yet have a GPG keyset, read this blog post on GPG keys. We can add a stack.yaml config setting to disable signing if some people desire it. We hope that people will sign. Later we will be adding GPG signature verification options.
  • stack build pkg-1.2.3 will now build even if the snapshot has a different package version - it is treated as an extra-dep. stack build local-pkg-1.2.3 is an error even if the version number matches the local package #2028.
  • Having a nix: section no longer implies enabling nix build. This allows the user to globally configure whether nix is used (unless the project overrides the default explicitly). See #1924.
  • Remove deprecated valid-wanted field.
  • Docker: mount home directory in container #1949.
  • Deprecate --local-bin-path instead --local-bin.
  • stack image: allow absolute source paths for add.

Other enhancements:

  • stack haddock --open [PACKAGE] opens the local haddocks in the browser.

  • Fix too much rebuilding when enabling/disabling profiling flags.

  • stack build pkg-1.0 will now build pkg-1.0 even if the snapshot specifies a different version (it introduces a temporary extra-dep)

  • Experimental support for --split-objs added #1284.

  • git packages with submodules are supported by passing the --recursive flag to git clone.

  • When using Hpack, only regenerate Cabal files when Hpack files change.

  • Hpack files can now be used in templates

  • stack ghci now runs ghci as a separate process #1306

  • Retry when downloading snapshots and package indices

  • Many build options are configurable now in stack.yaml:

      library-profiling: true
      executable-profiling: true
      haddock: true
      haddock-deps: true
      copy-bins: true
      prefetch: true
      force-dirty: true
      keep-going: true
      test: true
        rerun-tests: true
        additional-args: ['-fprof']
        coverage: true
        no-run-tests: true
      bench: true
        benchmark-arguments: -O2
        no-run-benchmarks: true
      reconfigure: true
      cabal-verbose: true
  • A number of URLs are now configurable, useful for firewalls. See #1794.

  • Suggest causes when executables are missing.

  • Allow --omit-packages even without --solver.

  • Improve the generated stack.yaml.

  • Improve ghci results after :load Main module collision with main file path.

  • Only load the hackage index if necessary #1883, #1892.

  • init: allow local packages to be deps of deps #1965.

  • Always use full fingerprints from GPG #1952.

  • Default to using gpg2 and fall back to gpg #1976.

  • Add a flag for –verbosity silent.

  • Add haddock --open flag #1396.

Bug fixes:

  • Package tarballs would fail to unpack. #1884.
  • Fixed errant warnings about missing modules, after deleted and removed from Cabal file #921 #1805.
  • Now considers a package to dirty when the Hpack file is changed #1819.
  • Nix: cancelling a Stack build now exits properly rather than dropping into a nix-shell #1778.
  • allow-newer: true now causes --exact-configuration to be passed to Cabal. See #1579.
  • stack solver no longer fails with InvalidRelFile for relative package paths including ... See #1954.
  • Ignore emacs lock files when finding Cabal files #1897.
  • Use lenient UTF-8 decode for build output #1945.
  • Clear index cache whenever index updated #1962.
  • Fix: Building a container image drops a .stack-work dir in the current working (sub)directory #1975.
  • Fix: Rebuilding when disabling profiling #2023.

Bug fixes:

  • Don’t delete contents of ~/.ssh when using stack clean --full with Docker enabled #2000

Build with path-io-1.0.0. There are no changes in behaviour from 1.0.4, so no binaries are released for this version.

Fixes build with aeson- There are no changes in behaviour from 1.0.4, so no binaries are released for this version.


Major changes:

  • Some notable changes in stack init:
    • Overall it should now be able to initialize almost all existing Cabal packages out of the box as long as the package itself is consistently defined.
    • Choose the best possible snapshot and add extra dependencies on top of a snapshot resolver rather than a compiler resolver - #1583
    • Automatically omit a package (--omit-packages) when it is compiler incompatible or when there are packages with conflicting dependency requirements. See #1674.
    • Some more changes for a better user experience. Please refer to the doc guide for details.
  • Add support for Hpack, alternative package description format #1679

Other enhancements:

  • Docker: pass ~/.ssh and SSH auth socket into container, so that git repos work #1358.
  • Docker: strip suffix from docker –version. #1653
  • Docker: pass USER and PWD environment variables into container.
  • On each run, Stack will test the Stack root directory (~/.stack), and the project and package work directories (.stack-work) for whether they are owned by the current user and abort if they are not. This precaution can be disabled with the --allow-different-user flag or allow-different-user option in the global config (~/.stack/config.yaml). #471
  • Added stack clean --full option for full working dir cleanup.
  • YAML config: support Zip archives.
  • Redownload build plan if parsing fails #1702.
  • Give mustache templates access to a ‘year’ tag #1716.
  • Have “stack ghci” warn about module name aliasing.
  • Add “stack ghci –load-local-deps”.
  • Build Setup.hs with -rtsopts #1687.
  • stack init accepts a list of directories.
  • Add flag infos to DependencyPlanFailures (for better error output in case of flags) #713
  • stack new --bare complains for overwrites, and add --force option #1597.

Bug fixes:

  • Previously, stack ghci would fail with cannot satisfy -package-id when the implicit build step changes the package key of some dependency.
  • Fix: Building with ghcjs: “ghc-pkg: Prelude.chr: bad argument: 2980338” #1665.
  • Fix running test / bench with --profile / --trace.
  • Fix: build progress counter is no longer visible #1685.
  • Use “-RTS” w/ profiling to allow extra args #1772.
  • Fix withUnpackedTarball7z to find name of srcDir after unpacking (fixes stack setup fails for ghcjs project on windows) #1774.
  • Add space before auto-generated bench opts (makes profiling options work uniformly for applications and benchmark suites) #1771.
  • Don’t try to find plugin if it resembles flag.
  • Setup.hs changes cause package dirtiness #1711.
  • Send “stack templates” output to stdout #1792.


Release notes:

Major changes:

  • stack init and solver overhaul #1583

Other enhancements:

  • Disable locale/codepage hacks when GHC >=7.10.3 #1552
  • Specify multiple images to build for stack image container docs
  • Specify which executables to include in images for stack image container docs
  • Docker: pass supplementary groups and umask into container
  • If git fetch fails wipe the directory and try again from scratch #1418
  • Warn if newly installed executables won’t be available on the PATH #1362
  • stack.yaml: for stack image container, specify multiple images to generate, and which executables should be added to those images
  • GHCI: add interactive Main selection #1068
  • Care less about the particular name of a GHCJS sdist folder #1622
  • Unified Enable/disable help messaging #1613

Bug fixes:

  • Don’t share precompiled packages between GHC/platform variants and Docker #1551
  • Properly redownload corrupted downloads with the correct file size. Mailing list discussion
  • Gracefully handle invalid paths in error/warning messages #1561
  • Nix: select the correct GHC version corresponding to the snapshot even when an abstract resolver is passed via --resolver on the command-line. #1641
  • Fix: Stack does not allow using an external package from ghci #1557
  • Disable ambiguous global ‘–resolver’ option for ‘stack init’ #1531
  • Obey --no-nix flag
  • Fix: GHCJS Execute.hs: Non-exhaustive patterns in lambda #1591
  • Send file-watch and sticky logger messages to stderr #1302 #1635
  • Use globaldb path for querying Cabal version #1647


Release notes:

  • We’re calling this version 1.0.0 in preparation for Stackage LTS 4. Note, however, that this does not mean the code’s API will be stable as this is primarily an end-user tool.


  • Added flag --profile flag: passed with stack build, it will enable profiling, and for --bench and --test it will generate a profiling report by passing +RTS -p to the executable(s). Great for using like stack build --bench --profile (remember that enabling profile will slow down your benchmarks by >4x). Run stack build --bench again to disable the profiling and get proper speeds
  • Added flag --trace flag: just like --profile, it enables profiling, but instead of generating a report for --bench and --test, prints out a stack trace on exception. Great for using like stack build --test --trace
  • Nix: all options can be overridden on command line #1483
  • Nix: build environments (shells) are now pure by default.
  • Make verbosity silent by default in script interpreter mode #1472
  • Show a message when resetting git commit fails #1453
  • Improve Unicode handling in project/package names #1337
  • Fix ambiguity between a Stack command and a filename to execute (prefer stack subcommands) #1471
  • Support multi line interpreter directive comments #1394
  • Handle space separated pids in ghc-pkg dump (for GHC HEAD) #1509
  • Add ghci –no-package-hiding option #1517
  • stack new can download templates from URL #1466

Bug fixes:

  • Nix: stack exec options are passed properly to the Stack sub process #1538
  • Nix: specifying a shell-file works in any current working directory #1547
  • Nix: use --resolver argument
  • Docker: fix missing image message and ‘–docker-auto-pull’
  • No HTML escaping for “stack new” template params #1475
  • Set permissions for generated .ghci script #1480
  • Restrict commands allowed in interpreter mode #1504
  • stack ghci doesn’t see preprocessed files for executables #1347
  • All test suites run even when only one is requested #1550
  • Edge cases in broken templates give odd errors #1535
  • Fix test coverage bug on windows

Bug fixes:

  • stack image container did not actually build an image #1473

Release notes:

  • The Stack home page is now at, which shows the documentation rendered by Note: this has necessitated some changes to the links in the documentation’s markdown source code, so please check the links on the website before submitting a PR to fix them.
  • The locations of the Ubuntu and Debian package repositories have changed to have correct URL semantics according to Debian’s guidelines #1378. The old locations will continue to work for some months, but we suggest that you adjust your /etc/apt/sources.list.d/fpco.list to the new location to avoid future disruption.
  • openSUSE and SUSE Linux Enterprise packages are now available, thanks to @mimi1vx. Note: there will be some lag before these pick up new versions, as they are based on Stackage LTS.

Major changes:

  • Support for building inside a Nix-shell providing system dependencies #1285
  • Add optional GPG signing on stack upload --sign or with stack sig sign ...

Other enhancements:

  • Print latest applicable version of packages on conflicts #508
  • Support for packages located in Mercurial repositories #1397
  • Only run benchmarks specified as build targets #1412
  • Support git-style executable fall-through (stack something executes stack-something if present) #1433
  • GHCi now loads intermediate dependencies #584
  • --work-dir option for overriding .stack-work #1178
  • Support detailed-0.9 tests #1429
  • Docker: improved POSIX signal proxying to containers #547

Bug fixes:

  • Show absolute paths in error messages in multi-package builds #1348
  • Docker-built binaries and libraries in different path #911 #1367
  • Docker: --resolver argument didn’t effect selected image tag
  • GHCi: Spaces in filepaths caused module loading issues #1401
  • GHCi: cpp-options in Cabal files weren’t used #1419
  • Benchmarks couldn’t be run independently of each other #1412
  • Send output of building setup to stderr #1410

Major changes:

  • GHCJS can now be used with stackage snapshots via the new compiler field.
  • Windows installers are now available: download them here #613
  • Docker integration works with non-FPComplete generated images #531

Other enhancements:

  • Added an allow-newer config option #922 #770
  • When a Hackage revision invalidates a build plan in a snapshot, trust the snapshot #770
  • Added a stack config set resolver RESOLVER command. Part of work on #115
  • stack setup can now install GHCJS on windows. See #1145 and #749
  • stack hpc report command added, which generates reports for HPC tix files
  • stack ghci now accepts all the flags accepted by stack build. See #1186
  • stack ghci builds the project before launching GHCi. If the build fails, try to launch GHCi anyway. Use stack ghci --no-build option to disable #1065
  • stack ghci now detects and warns about various circumstances where it is liable to fail. See #1270
  • Added require-docker-version configuration option
  • Packages will now usually be built along with their tests and benchmarks. See #1166
  • Relative local-bin-path paths will be relative to the project’s root directory, not the current working directory. #1340
  • stack clean now takes an optional [PACKAGE] argument for use in multi-package projects. See #583
  • Ignore cabal_macros.h as a dependency #1195
  • Pad timestamps and show local time in –verbose output #1226
  • GHCi: Import all modules after loading them #995
  • Add subcommand aliases: repl for ghci, and runhaskell for runghc #1241
  • Add typo recommendations for unknown package identifiers #158
  • Add stack path --local-hpc-root option
  • Overhaul dependencies’ haddocks copying #1231
  • Support for extra-package-dbs in ‘stack ghci’ #1229
  • stack new disallows package names with “words” consisting solely of numbers #1336
  • stack build --fast turns off optimizations
  • Show progress while downloading package index #1223.

Bug fixes:

  • Fix: Haddocks not copied for dependencies #1105
  • Fix: Global options did not work consistently after subcommand #519
  • Fix: ‘stack ghci’ doesn’t notice that a module got deleted #1180
  • Rebuild when Cabal file is changed
  • Fix: Paths in GHC warnings not canonicalized, nor those for packages in subdirectories or outside the project root #1259
  • Fix: unlisted files in tests and benchmarks trigger extraneous second build #838

Major changes:

  • stack setup now supports building and booting GHCJS from source tarball.
  • On Windows, build directories no longer display “pretty” information (like x86_64-windows/Cabal-, but rather a hash of that content. The reason is to avoid the 260 character path limitation on Windows. See #1027
  • Rename config files and clarify their purposes #969
    • ~/.stack/stack.yaml –> ~/.stack/config.yaml
    • ~/.stack/global –> ~/.stack/global-project
    • /etc/stack/config –> /etc/stack/config.yaml
    • Old locations still supported, with deprecation warnings
  • New command “stack eval CODE”, which evaluates to “stack exec ghc – -e CODE”.

Other enhancements:

  • No longer install git on Windows #1046. You can still get this behavior by running the following yourself: stack exec -- pacman -Sy --noconfirm git.
  • Typing enter during –file-watch triggers a rebuild #1023
  • Use Haddock’s --hyperlinked-source (crosslinked source), if available #1070
  • Use Stack-installed GHCs for stack init --solver #1072
  • New experimental stack query command #1087
  • By default, Stack no longer rebuilds a package due to GHC options changes. This behavior can be tweaked with the rebuild-ghc-options setting. #1089
  • By default, ghc-options are applied to all local packages, not just targets. This behavior can be tweaked with the apply-ghc-options setting. #1089
  • Docker: download or override location of Stack executable to re-run in container #974
  • Docker: when Docker Engine is remote, don’t run containerized processes as host’s UID/GID #194
  • Docker: set-user option to enable/disable running containerized processes as host’s UID/GID #194
  • Custom Setup.hs files are now precompiled instead of interpreted. This should be a major performance win for certain edge cases (biggest example: building Cabal itself) while being either neutral or a minor slowdown for more common cases.
  • stack test --coverage now also generates a unified coverage report for multiple test-suites / packages. In the unified report, test-suites can contribute to the coverage of other packages.

Bug fixes:

  • Ignore stack-built executables named ghc #1052
  • Fix quoting of output failed command line arguments
  • Mark executable-only packages as installed when copied from cache #1043
  • Canonicalize temporary directory paths #1047
  • Put code page fix inside the build function itself #1066
  • Add explicit-setup-deps option #1110, and change the default to the old behavior of using any package in the global and snapshot database #1025
  • Precompiled cache checks full package IDs on Cabal < 1.22 #1103
  • Pass -package-id to ghci #867
  • Ignore global packages when copying precompiled packages #1146

Major changes:

  • On Windows, we now use a full MSYS2 installation in place of the previous PortableGit. This gives you access to the pacman package manager for more easily installing libraries.
  • Support for custom GHC binary distributions #530
    • ghc-variant option in stack.yaml to specify the variant (also --ghc-variant command-line option)
    • setup-info in stack.yaml, to specify where to download custom binary distributions (also --ghc-bindist command-line option)
    • Note: On systems with libgmp4 (aka, such as CentOS 6, you may need to re-run stack setup due to the centos6 GHC bindist being treated like a variant
  • A new --pvp-bounds flag to the sdist and upload commands allows automatic adding of PVP upper and/or lower bounds to your dependencies

Other enhancements:

  • Adapt to upcoming Cabal installed package identifier format change #851
  • stack setup takes a --stack-setup-yaml argument
  • --file-watch is more discerning about which files to rebuild for #912
  • stack path now supports --global-pkg-db and --ghc-package-path
  • --reconfigure flag #914 #946
  • Cached data is written with a checksum of its structure #889
  • Fully removed --optimizations flag
  • Added --cabal-verbose flag
  • Added --file-watch-poll flag for polling instead of using filesystem events (useful for running tests in a Docker container while modifying code in the host environment. When code is injected into the container via a volume, the container won’t propagate filesystem events).
  • Give a preemptive error message when -prof is given as a GHC option #1015
  • Locking is now optional, and will be turned on by setting the STACK_LOCK environment variable to true #950
  • Create default stack.yaml with documentation comments and commented out options #226
  • Out of memory warning if Cabal exits with -9 #947

Bug fixes:

  • Hacky workaround for optparse-applicative issue with stack exec --help #806
  • Build executables for local extra deps #920
  • copyFile can’t handle directories #942
  • Support for spaces in Haddock interface files fpco/minghc#85
  • Temporarily building against a “shadowing” local package? #992
  • Fix Setup.exe name for --upgrade-cabal on Windows #1002
  • Unlisted dependencies no longer trigger extraneous second build #838

Fix stack’s own Haddocks. No changes to functionality (only comments updated).

Major changes:

  • You now have more control over how GHC versions are matched, e.g. “use exactly this version,” “use the specified minor version, but allow patches,” or “use the given minor version or any later minor in the given major release.” The default has switched from allowing newer later minor versions to a specific minor version allowing patches. For more information, see #736 and #784.
  • Support added for compiling with GHCJS
  • Stack can now reuse prebuilt binaries between snapshots. That means that, if you build package foo in LTS-3.1, that binary version can be reused in LTS-3.2, assuming it uses the same dependencies and flags. #878

Other enhancements:

  • Added the --docker-env argument, to set environment variables in Docker container.
  • Set locale environment variables to UTF-8 encoding for builds to avoid “commitBuffer: invalid argument” errors from GHC #793
  • Enable transliteration for encoding on stdout and stderr #824
  • By default, stack upgrade automatically installs GHC as necessary #797
  • Added the ghc-options field to stack.yaml #796
  • Added the extra-path field to stack.yaml
  • Code page changes on Windows only apply to the build command (and its synonyms), and can be controlled via a command line flag (still defaults to on) #757
  • Implicitly add packages to extra-deps when a flag for them is set #807
  • Use a precompiled Setup.hs for simple build types #801
  • Set –enable-tests and –enable-benchmarks optimistically #805
  • --only-configure option added #820
  • Check for duplicate local package names
  • Stop nagging people that call stack test #845
  • --file-watch will ignore files that are in your VCS boring/ignore files #703
  • Add --numeric-version option

Bug fixes:

  • stack init --solver fails if GHC_PACKAGE_PATH is present #860
  • stack solver and stack init --solver check for test suite and benchmark dependencies #862
  • More intelligent logic for setting UTF-8 locale environment variables #856
  • Create missing directories for stack sdist
  • Don’t ignore Cabal files with extra periods #895
  • Deprecate unused --optimizations flag
  • Truncated output on slow terminals #413

Bug fixes:

  • Ignore disabled executables #763

Major changes:

  • Detect when a module is compiled but not listed in the Cabal file (#32)
    • A warning is displayed for any modules that should be added to other-modules in the Cabal file
    • These modules are taken into account when determining whether a package needs to be built
  • Respect TemplateHaskell addDependentFile dependency changes (#105)
    • TH dependent files are taken into account when determining whether a package needs to be built.
  • Overhauled target parsing, added --test and --bench options #651

Other enhancements:

  • Set the HASKELL_DIST_DIR environment variable #524
  • Track build status of tests and benchmarks #525
  • --no-run-tests #517
  • Targets outside of root dir don’t build #366
  • Upper limit on number of flag combinations to test #543
  • Fuzzy matching support to give better error messages for close version numbers #504
  • --local-bin-path global option. Use to change where binaries get placed on a --copy-bins #342
  • Custom snapshots #111
  • –force-dirty flag: Force treating all local packages as having dirty files (useful for cases where Stack can’t detect a file change)
  • GHC error messages: display file paths as absolute instead of relative for better editor integration
  • Add the --copy-bins option #569
  • Give warnings on unexpected config keys #48
  • Remove Docker pass-host option
  • Don’t require cabal-install to upload #313
  • Generate indexes for all deps and all installed snapshot packages #143
  • Provide --resolver global option #645
    • Also supports --resolver nightly, --resolver lts, and --resolver lts-X
  • Make stack build --flag error when flag or package is unknown #617
  • Preserve file permissions when unpacking sources #666
  • stack build etc work outside of a project
  • list-dependencies command #638
  • --upgrade-cabal option to stack setup #174
  • --exec option #651
  • --only-dependencies implemented correctly #387

Bug fixes:

  • Extensions from the other-extensions field no longer enabled by default #449
  • Fix: haddock forces rebuild of empty packages #452
  • Don’t copy over executables excluded by component selection #605
  • Fix: Stack fails on Windows with git package in stack.yaml and no git binary on path #712
  • Fixed GHCi issue: Specifying explicit package versions (#678)
  • Fixed GHCi issue: Specifying -odir and -hidir as .stack-work/odir (#529)
  • Fixed GHCi issue: Specifying A instead of A.ext for modules (#498)

  • Add --prune flag to stack dot #487
  • Add --[no-]external,--[no-]include-base flags to stack dot #437
  • Add --ignore-subdirs flag to init command #435
  • Handle attempt to use non-existing resolver #436
  • Add --force flag to init command
  • exec style commands accept the --package option (see Reddit discussion)
  • stack upload without arguments doesn’t do anything #439
  • Print latest version of packages on conflicts #450
  • Flag to avoid rerunning tests that haven’t changed #451
  • Stack can act as a script interpreter (see [Script interpreter] ( and Reddit discussion)
  • Add the --file-watch flag to auto-rebuild on file changes #113
  • Rename stack docker exec to stack exec --plain
  • Add the --skip-msys flag #377
  • --keep-going, turned on by default for tests and benchmarks #478
  • concurrent-tests: BOOL #492
  • Use hashes to check file dirtiness #502
  • Install correct GHC build on systems with #465
  • stack upgrade checks version before upgrading #447

  • Remove GHC uncompressed tar file after installation #376
  • Put stackage snapshots JSON on S3 #380
  • Specifying flags for multiple packages #335
  • single test suite failure should show entire log #388
  • valid-wanted is a confusing option name #386
  • stack init in multi-package project should use local packages for dependency checking #384
  • Display information on why a snapshot was rejected #381
  • Give a reason for unregistering packages #389
  • stack exec accepts the --no-ghc-package-path parameter
  • Don’t require build plan to upload #400
  • Specifying test components only builds/runs those tests #398
  • STACK_EXE environment variable
  • Add the stack dot command
  • stack upgrade added #237
  • --stack-yaml command line flag #378
  • --skip-ghc-check command line flag #423

Bug fixes:

  • Haddock links to global packages no longer broken on Windows #375
  • Make flags case-insensitive #397
  • Mark packages uninstalled before rebuilding #365

  • Fall back to Cabal dependency solver when a snapshot can’t be found
  • Basic implementation of stack new #137
  • stack solver command #364
  • stack path command #95
  • Haddocks #143:
    • Build for dependencies
    • Use relative links
    • Generate module contents and index for all packages in project


  • --prefetch #297
  • upload command ported from stackage-upload #225
  • --only-snapshot #310
  • --resolver #224
  • stack init #253
  • --extra-include-dirs and --extra-lib-dirs #333
  • Specify intra-package target #201


  • Fix some Windows specific bugs #216
  • Improve output for package index updates #227
  • Automatically update indices as necessary #227
  • –verbose flag #217
  • Remove packages (HTTPS and Git) #199
  • Config values for system-ghc and install-ghc
  • Merge stack deps functionality into stack build
  • install command #153 and #272
  • overriding architecture value (useful to force 64-bit GHC on Windows, for example)
  • Overhauled test running (allows cycles, avoids unnecessary recompilation, etc)


  • First public release, beta quality