stack sdist (2.3.1) generates weird PVP bounds in .cabal file

[vaclavsvejcar]

General summary/comments (optional)

For my haskell project I use stack for building & generating tarball for Hackage. To generate PVP bounds in resulting .cabal file, I use the pvp-bounds: lower option in my stack.yaml. Everything worked fine with stack-2.1.3, but after upgrading to stack-2-3-1, running stack sdist results in following error:

Unable to parse cabal file from package /private/var/folders/fl/g3lf6zg14d7_5n2_rvs7ntgw0000gn/T/stack-450c73176363635d/headroom-0.2.2.0/headroom.cabal

- 147:17: 
unexpected Sublibrary dependency syntax used. To use this syntax the package needs to specify at least 'cabal-version: 3.0'. Alternatively, if you are depending on an internal library, you can write directly the library name as it were a package.
expecting space

When checking the generated .cabal file, I noticed that version bounds in dependencies section looks like this:

    build-depends:
        aeson : {} >=1.4.7.1,
        base : {} >=4.7 && <5,
        either : {} >=5.0.1.1,
        file-embed : {} >=0.0.11.2,

Note the {} which probably causes the issue. I tried to use Cabal 3 as suggested by changing several things in my package.yaml file gist, which suppresed all the warnings, but these {} remains in the generated .cabal file inside the distribution tarball. When trying to upload such tar to Hackage, it ends up with following error:

Invalid package

headroom-0.2.2.0/headroom.cabal:148:15: unexpected ':' expecting space, white space, opening paren, operator, comma or end of input aeson : {} >=1.4.7.1, base : {} >=4.7 && <5, either : {} >=5.0.1.1, file-embed : {} >=0.0.11.2, mustache : {} >=2.3.1, optparse-applicative : {} >=0.15.1.0, pcre-light : {} >=0.4.1.0, rio : {} >=0.1.15.1, template-haskell : {} >=2.15.0.0, time : {} >=1.9.3, yaml : {} >=0.11.3.0

Is this expected behaviour, or is it either stack or hpack bug or error in my configuration? Either way, I'm not able to generate valid distribution tarball for Hackage using stack-2.3.1.

Steps to reproduce

For example:

1. Clone https://github.com/vaclavsvejcar/headroom
2. Run stack sdist inside the project directory

Expected

.tar.gz distribution file that would be accepted by Hackage (as with stack-2.1.3)

Actual

Generated .tar.gz contains (probably) invalid syntax in .cabal file.

Stack version

$ stack --version
Version 2.3.1, Git revision de2a7b694f07de7e6cf17f8c92338c16286b2878 (8103 commits) x86_64 hpack-0.33.0

Method of installation

• Official binary, downloaded from stackage.org or fpcomplete's package repository

[rblaze]

Affects me too, I'll have to rollback to the older stack to publish new package.

[vaclavsvejcar]

@snoyberg Can you please confirm whether this is intended behaviour or bug and in case of bug, it it's problem of stack or rather hpack? Have no idea what causes this, but it's pretty unfortunate as I'm unable to generate working tarball with stack sdist using current version of stack.

[snoyberg]

Most likely it's a big in the Cabal library. We use its pretty printer, and it's been buggy in the past. I'd recommend turning off the pvp-bounds option. Due to these kinds of Cabal bugs, I've considered removing the feature

[dzhus]

The issue is in how stack uses the Cabal library – please see the PR #5309 linked above for the fix.

[sullyj3]

Given that #5309 was merged, does that close this issue?

[dzhus]

@sullyj3 I think so, yes. The fix is called out in https://github.com/commercialhaskell/stack/blob/master/ChangeLog.md#v233.

[snoyberg]

Thanks for the ping, closing