cabal tries to build package with incompatible dependencies

[chshersh]

Describe the bug

Sometimes bulds on CI fail for a very strange reason even locally everything passes. Cabal tries to find plan and uses incompatible versions of libraries. Here is the error when trying to build htoml-megaparsec dependency for tomland library:

Failed to build htoml-megaparsec-2.1.0.3.
Build log (
/home/travis/.cabal/logs/ghc-8.6.5/htoml-megaparsec-2.1.0.3-4b4579106a015b896d103c21db8f2fac3f5d24b1ecbd2f4464c4ae7e70f1d197.log
):
Configuring library for htoml-megaparsec-2.1.0.3..
Warning: The package has an extraneous version range for a dependency on an
internal library: htoml-megaparsec -any && ==2.1.0.3, htoml-megaparsec -any &&
==2.1.0.3. This version range includes the current package but isn't needed as
the current package's library will always be used.
Warning:
    This package indirectly depends on multiple versions of the same package. This is very likely to cause a compile failure.
      package htoml-megaparsec (htoml-megaparsec-2.1.0.3-a43bf81dd4ed16baa7df86402245273a070e296a75935859cc970333decde7c9) requires megaparsec-7.0.5-54d1bdf0ee32051801b7c529a69a41a0acc67473704149889aef5337a11842d2
      package htoml-megaparsec (htoml-megaparsec-2.1.0.3) requires megaparsec-7.0.5-9a3f6cbc12071475f205b18cb99b964689c854f3fb71eaf81d216338d2693951
      package megaparsec (megaparsec-7.0.5-54d1bdf0ee32051801b7c529a69a41a0acc67473704149889aef5337a11842d2) requires parser-combinators-1.1.0-4a323801805b1b1e8dc52a5c2286803ad99ec50727aae4428d88e6488abdd583
      package megaparsec (megaparsec-7.0.5-9a3f6cbc12071475f205b18cb99b964689c854f3fb71eaf81d216338d2693951) requires parser-combinators-1.2.0-81eabffcf72fb987500cc5956d9da1d7de5f06d979d7ea0c2614ddbf9c0421ec
Preprocessing library for htoml-megaparsec-2.1.0.3..
Building library for htoml-megaparsec-2.1.0.3..
[1 of 1] Compiling Text.Toml        ( src/Text/Toml.hs, dist/build/Text/Toml.o )

src/Text/Toml.hs:22:16: error:
    • Couldn't match type ‘ParseErrorBundle Text e0’
                     with ‘megaparsec-7.0.5:Text.Megaparsec.Error.ParseErrorBundle
                             Text Data.Void.Void’

You can find the full log here:

• https://pastebin.com/w8byLmC1

To Reproduce

Cannot reproduce locally. Locally everything works for me.

Expected behavior

Successful builds.

Additional context

Using cabal-3.0 on Travis CI.

[phadej]

The log says

$ cabal --version
cabal-install version 3.0.0.0

have you tried with cabal-install-3.0 locally?

[chshersh]

@phadej My mistake. Fixed the cabal version in description. Yeah, it works locally with both cabal-2.4 and cabal-3.0.

[Mikolaj]

Thank you for reporting. I think this is fixed in cabal 3.4. Please let us know if you can repro this with 3.4 or newer cabals. In any case, closing as a duplicate of #5782.