Any chance for a test?

Changelog would be nice too.

As requested, I've add something to Cabal's ChangeLog (I hope it was the correct file) and also to cabal-install's (as it flows through to the tool, too).

I can't think of how to test for the original mistake.

There's a changelog.d directory into which changelog fragments go, rather than edit the ChangeLog directly; this lets changelogs be built for a particular version from the commits that go into that version.

Thanks! The explanation about changelogs is referenced in the PR template.

@geekosaur, @ulysses4ever apologies on ChangeLog. I've now read the instructions, and tried again.

For testing: could you create a copy of cabal-testsuite/PackageTests/NewHaddock/HaddockOutput/HaddockOutputCmd, rename it, change the call to cabal in cabal.test.hs from

  r <- cabal' "haddock" ["--haddock-output-dir=docs", "A"] 

to

  r <- cabal' "haddock" ["--haddock-output-dir=docs", " --haddock-for-hackage" "A"] 

and replace the last line in the same file (assertFindInFile...) with assertOutputDoesNotContain "index.html" r?

I may be missing some details but high-level this is the way to go, I think.

To test is locally you may need to dive into https://github.com/haskell/cabal/blob/master/cabal-testsuite/README.md Most importantly, --with-cabal should be set correctly (e.g. to $(cabal list-bin cabal) after you have built cabal).

@ulysses4ever, I have added a test but my attempts to test the test locally came to naught, because Test.Cabal.Prelude.withRepo contains a skipIfWindows. So, I am relying on CI to test the test. EDIT: Well that did not work ... I am retrying with a simpler test. EDIT2: Well that did not work either. Perhaps it is something to do with the cabal.out file ... I am retrying with one.

Thank you for willing to give it a go, and I'm sorry it doesn't go through yet.

withRepo may actually be not necessary. You could try any other existing test that calls cabal against a local package instead of a dependency (withRepo is only necessary when a test package uses a dependency).

Sorry, didn't see the edits until now (better send new comments — for visibility). Yes, .out will need to be adjusted. Usually it's done by calling the test binary with --accept but if you can't run it locally, this may be a problem...

@ulysses4ever, I finally arrived at a test that has passed the CI.