Explicit project (Was: #585)

[alang9]

This is continued from #585. We've added some tests and travis runs now succeed.

[lierdakil]

This fails to build on GHC 8.0.1:

Language/Haskell/GhcMod/Gap.hs:681:11: error:
    Variable not in scope: cleanTempFiles :: DynFlags -> IO a0

Language/Haskell/GhcMod/Gap.hs:682:11: error:
    Variable not in scope: cleanTempDirs :: DynFlags -> IO a1

[DanielG]

Could you explain what you're doing here? Looking at what explicitCradle above it seems that when the project type is ExplicitCradle """cradleCabalFile""" would always be: cradleCabalFile = Just optionsFile which seems like a horrible misnomer in its own right ;)

Also maybe you could put the optionsFile in the ExplicitProject constructor like we do with the StackEnv stuff?

[DanielG]

Those binary package.cache files are sure to break at some point, do you absolutely need them? Maybe those can just be empty or something? Either way we already do package-db setup in the test Main, maybe you can re-use that: https://github.com/DanielG/ghc-mod/blob/master/test/Main.hs#L26

[DanielG]

This is no good, there is a reason we do this in another process (memory usage). Please revert.

[DanielG]

@lierdakil this PR doesn't even touch Gap, wtf?

[lierdakil]

It's probably just needs rebasing on current master =\

[lierdakil]

Okay, so you don't want to check in package.cache into repo, since it's ghc-specific binary format which can (and will) change, and your tests will fail for no good reason with something like
GHC.PackageDb.readPackageDb: inappropriate type (not a ghc-pkg db file, wrong file magic number)

[DanielG]

ETIMEDOUT, closing. Feel free to reopen if you still want to work on this.