Nix fails when Cabal 2.4 wildcard paths feature is used

[mrkkrp]

Issue description

Nix fails when Cabal 2.4 wildcard paths feature is used. The feature allows us to use ** in paths when we specify collections of e.g. data files. Instead of respecting that, current nixpgks creates a directory literally called ** and so install phase fails because of that.

Steps to reproduce

Clone this branch of Ormolu:

tweag/ormolu#149

where I try to make use of the feature.

Then just do nix-build.

The failure is also visible in respective Circle CI logs here:

https://circleci.com/gh/tweag/ormolu/535?utm_campaign=vcs-integration-link&utm_medium=referral&utm_source=github-checks-link

Technical details

• system: "x86_64-linux"
• host os: Linux 4.19.34, NixOS, 19.03.git.f52505f (Koi)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3pre6631_e58a7144
• channels(mark): "nixos-18.09.2337.5d972dd2c94"
• nixpkgs: /home/mark/nixpkgs

(I don't believe the info has any significance in this case.)

[cdepillabout]

I took a look at this, but I am having trouble getting the branch you linked to working with just plain cabal.

At the end of the nix-build for Haskell packages, Setup install or Setup copy is called:

nixpkgs/pkgs/development/haskell-modules/generic-builder.nix

Lines 409 to 413 in f3282c8

	installPhase = ''
	runHook preInstall
	${if !isLibrary then "${setupCommand} install" else ''
	${setupCommand} copy

This is what is failing.

However, I couldn't figure out why this would be failing, so I tried to reproduce it with just cabal. Setup install and Setup copy should be relatively similar to just calling cabal install, cabal copy, or cabal new-install.

Each of these commands appears to fail as well.

First, the setup for running cabal:

$ git clone ...
$ cd ormolu/
$ nix-shell

Now try with cabal copy:

$ cabal build
(succeeds...)
$ cabal copy
/home/illabout/.cabal/share/x86_64-linux-ghc-8.6.4/ormolu-0.0.1.0/data/examples/import: copyFile: does not exist (No such file or directory)

Try with cabal install:

$ cabal install
Resolving dependencies...
Starting     ormolu-0.0.1.0
Building     ormolu-0.0.1.0
Failed to install ormolu-0.0.1.0
Build log ( /home/illabout/.cabal/logs/ghc-8.6.4/ormolu-0.0.1.0-FG1czeAr5Q63OC8on7h99e.log ):
cabal: Entering directory '.'
Configuring ormolu-0.0.1.0...
Preprocessing library for ormolu-0.0.1.0..
Building library for ormolu-0.0.1.0..
Preprocessing executable 'ormolu' for ormolu-0.0.1.0..
Building executable 'ormolu' for ormolu-0.0.1.0..
/home/illabout/.cabal/share/x86_64-linux-ghc-8.6.4/ormolu-0.0.1.0/data/examples/import: copyFile: does not exist (No such file or directory)
cabal: Leaving directory '.'
cabal: Error: some packages failed to install:
ormolu-0.0.1.0-FG1czeAr5Q63OC8on7h99e failed during the final install step.
The exception was:
ExitFailure 1

Try with cabal new-install:

$ cabal new-build
(succeeds...)
$ cabal new-install exe:ormolu
Resolving dependencies...
Build profile: -w ghc-8.6.4 -O1
In order, the following will be built (use -v for more details):
 - ormolu-0.0.1.0 (lib) (requires build)
 - ormolu-0.0.1.0 (exe:ormolu) (requires build)
Starting     ormolu-0.0.1.0 (lib)
Building     ormolu-0.0.1.0 (lib)
Installing   ormolu-0.0.1.0 (lib)
Warning: Some package(s) failed to build. Try rerunning with -j1 if you can't
see the error.

Failed to build ormolu-0.0.1.0. The failure occurred during the final install
step.
Build log (
/home/illabout/.cabal/logs/ghc-8.6.4/ormolu-0.0.1.0-92a9154ca931fd51a93dff32cdbea6dc0ddb6dbdc5d057c74b04741d826ca4f7.log
):
Configuring library for ormolu-0.0.1.0..
Preprocessing library for ormolu-0.0.1.0..
Building library for ormolu-0.0.1.0..
[ 1 of 33] Compiling Ormolu.Anns      ( src/Ormolu/Anns.hs, dist/build/Ormolu/Anns.o )
[ 2 of 33] Compiling Ormolu.CommentStream ( src/Ormolu/CommentStream.hs, dist/build/Ormolu/CommentStream.o )
[ 3 of 33] Compiling Ormolu.Config    ( src/Ormolu/Config.hs, dist/build/Ormolu/Config.o )
...
[32 of 33] Compiling Ormolu.Diff      ( src/Ormolu/Diff.hs, dist/build/Ormolu/Diff.o )
[33 of 33] Compiling Ormolu           ( src/Ormolu.hs, dist/build/Ormolu.o )
/home/illabout/.cabal/store/ghc-8.6.4/incoming/new-12791/home/illabout/.cabal/store/ghc-8.6.4/ormolu-0.0.1.0-92a9154ca931fd51a93dff32cdbea6dc0ddb6dbdc5d057c74b04741d826ca4f7/share/data/printer: copyFile: does not exist (No such file or directory)
cabal: Failed to build ormolu-0.0.1.0 (which is required by exe:ormolu from
ormolu-0.0.1.0). See the build log above for details.

The cabal documentation suggests that the data-files line in ormolu.cabal should work, so my guess is that this is a cabal bug:

https://cabal.readthedocs.io/en/latest/developing-packages.html#pkg-field-data-files

[mrkkrp]

The corresponding Cabal issue appears to be fixed now.