cabal should fail if compilation depends on a file not existing in the cabal file

[bos]

(Imported from Trac #949, reported by LeventErkok on 2012-05-11)

Cabal doesn't complain if the build depends on a Haskell module that exists in the filesystem properly, but is not mentioned in the cabal file itself as part of "exposed-modules" or "other-modules". The build succeeds because ghc can find the relevant file just fine.

I've got bitten by this several times, especially after pushing a package to hackage, only to get it fail to build on the server because I've failed to put the name of a file in the appropriate section of the cabal file, thus it didn't make it to the .tar.gz bundle that got uploaded to the server.

I realize this might be hard to ensure, as it would require a deeper look into the dependencies between modules, but I trust the GHC API should have all the information necessary for cabal to complain appropriately.

[thielema]

On my 64bit machine I got the following strange linker error when I forgot to register a module in the Cabal file:

/usr/bin/ld: dist/build/.../Module.dyn_o: relocation R_X86_64_PC32 against undefined symbol `..._xyz1_closure' can not be used when making a shared object; recompile with -fPIC

[timthelion]

I second this as a bug! We ran into this https://github.com/colah/ImplicitCAD/issues/61 it is quite a nasty little bugger when all you get is a link error with no info. If this can't be fixed in cabal, perhaps GHC could at least give us a hint as to the source of the link error?

[timthelion]

See issue: https://github.com/haskell/cabal/issues/22

[dagit]

I just helped someone in #haskell with this problem. For them it was appearing because their test-suite section depended on a package that forgot to mention some modules in the other-modules list.

I found the solution by search my irc logs for the last time I helped someone with this. What I'm trying to say is, this is a pretty common problem. Is there any way to increase the priority of this bug? Perhaps adding it to the next milestone.

Thanks!

[23Skidoo]

This requires either parsing the output of ghc -M or a GHC option to blacklist all modules not included in exposed-modules and other-modules.

[MedeaMelana]

Hi, I just ran into this problem again. I thought I'd bump this issue because it hasn't received any attention in a while and I believe it's important enough to fix. Also I believe this should be labeled as bug rather than enhancement because cabal doesn't produce a valid library if someone forgets to mention a module in their cabal file.

[schell]

I just ran into this myself with https://github.com/schell/steeloverseer/issues/6. It looks like I deleted the "other-modules" line of my cabal file at some point trying to clean it up. /facepalm

[ttuegel]

Duplicate of #1746.