Option to run test suites after sdist

[snoyberg]

Just floating an idea here. A very common test suite failure is that some source file is included in source control, but not included in the sdist. Usually the fix is simple: add the extra file to extra-source-files. But it would be nice to have this kind of check built into cabal-install. Perhaps something along the lines of exposing cabal sdist --check which:

• Runs a cabal check
• Create a tarball
• Unpacks the tarball into a temporary folder
• Runs cabal configure --enable-tests && cabal build && cabal test from that folder.

[tibbe]

I would like to go one step further and make sure that building and running tests doesn't happen in the source directory but in some other directory, such that any files not listed in the .cabal file simply won't be found by the compiler and thus causes a compilation error in cabal build.

One way to achieve this (that probably won't work on Windows) is to symlink all the files listed in the .cabal file to another directory and run the build there.

[23Skidoo]

Perhaps something along the lines of exposing cabal sdist --check

Alternatively, we can call this cabal check --sdist or just make check work like this by default.