cabal list-bin is broken

[athas]

Since b2be49c (#8622) cabal list-bin no longer produces any output on any project I try it on. If I change the use of info back to putStrLn, it works again.

Steps to reproduce the behavior: In the cabal repository itself: cabal list-bin cabal

It is also possible that I am holding it wrong (I don't understand this entire info machinery), but I don't see how a command like list-bin can possibly require any complexity or subtle behaviour.

[athas]

Changing the flag passed to info to verbose also makes it work, but perhaps someone savvy about this system should weigh in. The info function does nothing if the passed-in verbosity isn't at least verbose, so to me it makes no sense to ever pass it a constant.

[ulysses4ever]

@athas great catch, thanks! I think, the right way to do it is notice verbosity instead of the current info normal. Could you try that and, if satisfied, submit a patch, please?

[fgaz]

I think we shouldn't use logging functions for that. This isn't a log, it's normal output. I'd expect list-bin to print out the path even with -v0.

[fgaz]

And we really need a test for list-bin. This isn't the first time it breaks

[ulysses4ever]

@fgaz that makes sense. If you read the initial ticket by @andreasabel #8400, it seems there was an argument for that had to do with the desire to have some more control than what what a mere putStrLn gives. But perhaps, it's not what we want and indeed, your example with -v0 makes perfect sense.

[andreasabel]

The intention of #8400 was to make it possible to get a test for list-bin in our current test framework (which catches marked output). In #8622, no test was added; it was a mistake to approve it nevertheless, my apologies.
Maybe the immediate action would be to revert #8622, and reopen #8400, and then fix #8400 properly with test.

Refs:

• cabal list-bin does not produce marked output #8400
• add marked output to cabal list-bin #8622

[athas]

That sounds like right way to go for now.

[athas]

And I suppose an actual solution might just use withOutputMarker directly, but someone familiar with the Verbosity system should probably weigh in.

[andreasabel]

Turns out we had a test case for list-bin contributed in #7925, but it didn't catch the main output (path to executable) because of #8400. A correct fix of #8400 should have touched the output of this testcase.
There is even another test contributed by @bacchanalia which should also benefit from a proper fix of #8400. I feel like both of these tests have to be revised to actually check that the path to the binary is produced by list-bin (atm, they succeed without checking that).

Ref:

• https://github.com/haskell/cabal/tree/bcfc79ce1e286b1df1fef31139044c0e0503d5c7/cabal-testsuite/PackageTests/ListBin

[andreasabel]

I have an emergency fix at #8668 (revert #8622) and a proper fix at #8670 which makes the emergency fix obsolete if merged quickly enough.

[ulysses4ever]

I also screwed up with approving the patch. Thank you Andreas for quickly acting on this!

[athas]

Lovely! Thanks for the fix. Now my hacky Makefile will work a little while longer.

[Bodigrim]

Reopening, the fix in #8670 misses a newline character. Depending on your terminal emulator it might look a bit different.

In zsh:

$ cabal-3.8.1.0 list-bin bytestring-tests
/Users/andrew/programs/bytestring/dist-newstyle/build/aarch64-osx/ghc-9.2.5/bytestring-0.11.3.1/t/bytestring-tests/build/bytestring-tests/bytestring-tests

but look at the last character:

$ cabal list-bin bytestring-tests
Warning: this is a debug build of cabal-install with assertions enabled.
/Users/andrew/programs/bytestring/dist-newstyle/build/aarch64-osx/ghc-9.2.5/bytestring-0.11.3.1/t/bytestring-tests/build/bytestring-tests/bytestring-tests%

[Mikolaj]

We'd also need a new test that checks the newline.

[andreasabel]

We'd also need a new test that checks the newline.

This isn't directly in the scope of the test framework, since it adds the newline:

cabal/Cabal/src/Distribution/Simple/Utils.hs

Lines 622 to 625 in a78d77b

	withOutputMarker _ xs =
	"-----BEGIN CABAL OUTPUT-----\n" ++
	withTrailingNewline xs ++
	"-----END CABAL OUTPUT-----\n"

[andreasabel]

Reopening, the fix in #8670 misses a newline character.

Since I am assigned to this issue, I will suggest a PR.

• Fix #8664 redux: add EOL character to list-bin output #8691