Research project funding work on small (2-4 hour) cabal ecosystem issues

[mpickering]

I have received funding to participate in a research study which will fund 40 hours of work on cabal ecosystem issues during the month of March.

If you have a small issue which you would like to see fixed then please link it in the discussion and I will investigate it over the next month.

The only criteria for the issue is that it will take me < 4 hours to solve.

I am going to start working on this project next week (Tuesday) and I need a list of 10 issues to get started from. I want to prioritise working on things which community members feel important.

[alt-romes]

Possibly #9752

[Mikolaj]

Here's the monster search formula for urgent labeled issues (some may be outdated or with a fix in progress): https://github.com/haskell/cabal/issues?q=state%3Aopen%20(label%3A%22priority%3A%20high%20%3Afire%3A%22%20OR%20label%3A%22regression%20in%203.12%22%20OR%20label%3A%22regression%20in%203.14%22%20OR%20label%3A%22regression%20in%203.0%22%20OR%20label%3A%22regression%20in%203.4%22%20OR%20label%3A%22regression%20in%203.6%22%20OR%20label%3A%22regression%20in%203.8%22%20OR%20label%3A%22regression%20in%203.10%22%20OR%20label%3A%22regression%20on%20master%22%20OR%20label%3A%22type%3A%20regression%22)%20

Edit: these tickets are/were also important: https://github.com/orgs/haskell/projects/10

[ffaf1]

I see it is AI stuff.

I would then pick something that is not hairy logic-wise, but could benefit from an amassed wealth of knowledge. #10295 or similar could be suited.

[grayjay]

I looked through the solver issues and found a few that are concrete and relatively simple, though probably not under four hours. It may be possible to split them, though.

1. Distinguish between deprecated and non-preferred versions in the package index hackage-server#1345 This change to Hackage would unblock multiple feature requests related to marking or avoiding deprecated package versions in cabal.
2. Remove single instance restriction from dependency solver for v2-build #6459 This change could allow us to make large improvements to solver performance, especially solving for setup or build tool dependencies. The first step could be to add a new parameter to the solver and write a unit test (which may fail initially).
3. Consider removing the "count conflicts" solver feature, since it may be redundant with "fine grained conflicts" #8931 This issue is mostly refactoring, though it would also require running and interpreting the solver benchmarks.

[ulysses4ever]

For a while now, I've been collecting low/moderate-effort issues that keep popping up here and there. Below is the list (after removing a couple of purely documentation issues). I hope it's not overwhelming.

• gen-bounds does not work in multiprojects
  Issue gen-bounds does not work in multiprojects #7504

• Use a local secure repositories in the test-suite. by andreabedini
  Pull Request Use a local secure repositories in the test-suite. #9540

• Consider reverting default usage of --enable-documentation in cabal haddock
  Issue Consider reverting default usage of --enable-documentation in cabal haddock #8725

• cabal repl load single module
  Issue cabal repl load single module #2592

• Per-Version Index Cache in ~/.cabal directory
  Issue Per-Version Index Cache in ~/.cabal directory #7502

• Flag to upload to auto-build and upload docs as well
  Issue Flag to upload to auto-build and upload docs as well #8249

• local packages with install-includes fail to expose headers
  Issue local packages with install-includes fail to expose headers #4517

• cabal freeze should take current set of packages installed into account
  Issue cabal freeze should take current set of packages installed into account #2520

• Warn when external Setup uses old Cabal by ttuegel
  Pull Request Warn when external Setup uses old Cabal #3801

• Relink-only seems to mess up dependency tracking
  Issue Relink-only seems to mess up dependency tracking #2976

• RFC: change default for logging to +nowrap
  Issue RFC: change default for logging to +nowrap #5488

• cabal v2-install ignores flag --run-tests
  Issue cabal v2-install ignores flag --run-tests #7267

• The --repl-no-load option is not recognized for build-type: Custom
  Issue The --repl-no-load option is not recognized for build-type: Custom #8379

• cabal new-build doesn't produce logs for local packages
  Issue cabal new-build doesn't produce logs for local packages #5901

• cabal cannot find cabal.project or *.cabal unless packages is defined
  Issue cabal cannot find cabal.project or *.cabal unless packages is defined #5850

• Make packages: . the default even when cabal.project exists.

• Make commas optional in "build-depends"
  Issue Make commas optional in "build-depends" #8479

• ci: github action error annotations despite passing tests
  Issue ci: github action error annotations despite passing tests #8419

• No valid value for license appropriate for proprietary code
  Issue No valid value for license appropriate for proprietary code #5697

• Troubles with setting the license field
  Issue Troubles with setting the license field #7971

• CI: consider publishing nightly builds via GHCup metadata channel
  Issue CI: consider publishing nightly builds via GHCup metadata channel #8932

• Local no-index repositories cache leads to bad UX
  Issue Local no-index repositories cache leads to bad UX #9136

• cabal repl: Change in PATH environment variable not reflected
  Issue cabal repl: Change in PATH environment variable not reflected #2015

• documentation: True outputs to stdout when -v0 is enabled
  Issue documentation: true outputs to stdout when -v0 is enabled #5991

[mpickering]

Thanks for the suggestions. You may have seen that I made some PRs already. The issue list I am working from at the moment is the following:

n	link	title
1	#2015	cabal repl: Change in PATH environment variable not reflected
2	#10783	Add a test for the issue fixed by the contributor
3	#10295	Make cabal check reject packages with invalid file names #10295
4	#10810	Allow containers-0.8
5	#7504	gen-bounds does not work in multiprojects
6	#10718	Write reproducer for Cabal 3.14.1.0 invokes test binaries with a corrupt (duplicated) environment variable list
7	#10718	Cabal 3.14.1.0 invokes test binaries with a corrupt (duplicated) environment variable list
8	#10759	Write reproducer for cabal-install 3.14 linking fails with "shared object file not found"
9	#10759	cabal-install 3.14 linking fails with "shared object file not found"
10	#10717	Regression: Cabal-3.14.1.0: v1-test, Setup.hs test: test suites of alex-3.4.0.1 and happy-1.20.1.1 unable to find data files
11	#10717	Writing test for Regression: Cabal-3.14.1.0: v1-test, Setup.hs test: test suites of alex-3.4.0.1 and happy-1.20.1.1 unable to find data files
12	#10797	Pass C++ environment variables to configure scripts
13	#8419	ci: github action error annotations despite passing tests
14	#7502	Per-Version Index Cache in ~/.cabal directory #7502
15	#10744	devx: Fix whitespace job output is too verbose
16	#10726	plan.json doesn't include compiler id
17	#10775	"Error: Dependency on unbuildable library" with three internal libraries and --enable-multi-repl

[mpickering]

Thanks everyone, the project has concluded now. I have written a blog post summarising the work - https://well-typed.com/blog/2025/04/ai-impact-open-source-haskell/

[ulysses4ever]

I enjoyed reading the post, thanks for linking (and writing) it! And thanks for choosing Cabal for this study!