doctest doesn't compile with GHC 7.7 snapshot

[peti]

Building doctest-0.9.7...
Preprocessing library doctest-0.9.7...
[ 1 of 13] Compiling Paths_doctest    ( dist/build/autogen/Paths_doctest.hs, dist/build/Paths_doctest.o )
[ 2 of 13] Compiling Interpreter      ( src/Interpreter.hs, dist/build/Interpreter.o )
[ 3 of 13] Compiling Help             ( src/Help.hs, dist/build/Help.o )
[ 4 of 13] Compiling Util             ( src/Util.hs, dist/build/Util.o )
[ 5 of 13] Compiling Runner.Example   ( src/Runner/Example.hs, dist/build/Runner/Example.o )
[ 6 of 13] Compiling Location         ( src/Location.hs, dist/build/Location.o )
[ 7 of 13] Compiling GhcUtil          ( src/GhcUtil.hs, dist/build/GhcUtil.o )

src/GhcUtil.hs:8:25: Module `Panic' does not export `ghcError'

[sol]

Thanks for the heads up. @kazu-yamamoto worked on this. But it seems that GHC HEAD changed again...

[kazu-yamamoto]

I'm not busy in September. So, I will try this again very soon.

[sol]

@kazu-yamamoto Thanks a lot!

[kazu-yamamoto]

Uhhm. I tested doctest HEAD with GHC HEAD. GHC HEAD can compile doctest HEAD. The test failures were exactly what I expected (i.e. future work). Am I missing something?

[peti]

Duh, you are right! The build error I saw was caused by a dependency of doctest. I just misread the build log. :-( I am sorry for the false report.

[kazu-yamamoto]

No problem!

[peti]

@kazu-yamamoto, could you please check out the build log at http://hydra.cryp.to/build/12672/nixlog/1/raw? The doctest build fails, saying:

src/GhcUtil.hs:8:25: Module `Panic' does not export `ghcError'

[kazu-yamamoto]

doctest 0.9.7 does not support GHC head. doctest head does support GHC head.

[peti]

Is there any particular reason why the release version of doctest doesn't build with GHC 7.7.x?

[kazu-yamamoto]

It's up to @sol. Note that doctest head does not pass 5 test cases at this moment.

[sol]

@peti I see how this can be an issue for nix, but the GHC API is a moving target and I can't guarantee that Doctest always works with GHC HEAD. @kazu-yamamoto already took quite some effort to make it work (big thanks for that!) and we can cut a new release as soon as all tests pass. But I'm currently somewhat swamped, so any help with this is much appreciated.

[peti]

@sol, thank you for the heads up. I have been trying to compile our package set in Nix with a recent snapshot of GHC, just to see how far that would go. It turns out that virtually nothing compiles, because some of the foundations won't build (such as test-framework, doctest, etc.), and almost all packages depend on some of those packages. So I started filing issues to make sure people are aware of the fact. I realize it's impossible to support GHC 7.7 at this time because -- strictly speaking -- there is no GHC 7.7. There's just a HEAD version of some Git repository. :-)

I am glad to see that Kazu and you make an effort to keep doctest working with a recent GHC snapshot. Thank you for your efforts. I'll look forward to a new release of doctest whenever it's ready. Once it comes out, I'll give this GHC 7.7 project another go.

[kazu-yamamoto]

I recorded issues to describe what I'm fighting against now. See #57,#58,#59.

[kazu-yamamoto]

OK. All bugs have been fixed now.

@sol, I think you can release a new version. I will tackle cabal sandbox.

[sol]

#57 and #58 look good to me.

I still wonder whether #57 is a regression in GHC? You should always flush stderr if an error happened, right?

I think #59 does not really solve the underlying issue, I propose #60 here.

[kazu-yamamoto]

Now I don't think #57 is regression in GHC. Stderr of GHC has BlockBuffering Nothing after hDuplicateTo. So, no flushing is reasonable. GHC 7.6.3 flushes stderr even if it has BlockBuffering Nothing. It was strange.

[peti]

I have a regression after the last doctest update. See http://hydra.cryp.to/build/25221/nixlog/15/raw for a complete build log. The problem seems to be that discardStaticFlags is not exported by the StaticFlag module. Admittedly, my ghc snapshot is old'ish, so this issue might not occur in more recent versions.

[sol]

@peti Yes, I guess your build is too old.