Krank checks your code source comments for important markers

Version on this page:0.2.2
LTS Haskell 21.25:0.3.0
Stackage Nightly 2023-06-21:0.3.0
Latest on Hackage:0.3.0

See all snapshots krank appears in

BSD-3-Clause licensed by Guillaume Bouchard
Maintained by [email protected]
This version can be pinned in stack with:krank-0.2.2@sha256:10211c8145d112f18daebb5c226f5520c8de2d1e666079857065f091ac3e974a,3204


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Krank checks your code source comments for important markers.

Comments are part of our code and are not usually tested correctly. Hence their content can become incoherent or obsolete. Krank tries to avoid that by running checkers on the comments themselves.


Just launch the krank command with a list of files as arguments. It works on any kind of source code file and prints a report of informations found in the comments:

$ krank $(git ls-files)

default.nix:20:20: info:
  still Open:

foo.hs:67:11: error:
  now Closed:

krank will fail (i.e. non-zero exit code) in case of any error.

Here krank is telling us that our source code links to github issues which are now closed. Time to remove some workarounds now that upstream issues are fixed!

You can check krank --help for a list of options, such as configuring your API token for external services, such as github and gitlab.

Available checkers

  • IssueTracker is listing Github and Gitlab issue linked in comment. Issues which are still Open will be listed as info and Closed issues are listed as error. Convenient to know when to remove workarounds.

Red herring

If you want to ignore all krank checkers on a given line of code, add krank:ignore-line on this same line. Krank will then skip this line and not report anything on it



Revision history for krank

0.2.2 – 2020-06-30

  • #84 fix build with unordered-containers
  • #81, new --version command line argument

0.2.1 – 2020-05-02

  • #76 fix. ignore space in URL
  • Output now includes the issue title.

0.2.0 – 2020-04-19

  • GHC 8.10 support
  • Output is more compact and more detailed.
  • Output is now colored (can be disabled with --no-colors).
  • Gitlab support. See --issuetracker-gitlabhost for host / api key pairs.
  • Huge performance improvement. Parsing a huge codebase should only be a matter of a few seconds.
  • Parallel request execution. Requests to the issue tracker host are not sequential anymore. This can dramatically reduce the runtime.
  • Ignore line. Add krank:ignore-line in your comments and the associated closed issue won’t be seen as an error anymore.
  • Failure mode: krank will return non 0 exit code if an issue is closed (an not ignored). – 2019-10-21

  • First version. Released on an unsuspecting world.
  • Support for Github issues tracking