stack build --no-copy-bins still invokes copy

[W4RH4WK]

I recently encountered an issue where a shared library ends up without symbols after invoking stack build. At first I thought this was a bug in stack since cabal build did fine. I reported this in #1925, but after further investigating this issue I found out that stack invokes cabal copy after the actual build process.

Cabal's copy command will run strip on a shared library to remove all the symbols. Logically I ran stack with the --no-copy-bins flag to prevent it from running cabal copy.

But this didn't help, looking at the verbose output, copy is still run:

$ stack build --no-copy-bins --verbose --cabal-verbose
        ...
2016-03-22 13:49:58.696840: [debug] Run process: /root/.stack/setup-exe-cache/x86_64-linux/setup-Simple-Cabal-1.22.5.0-ghc-7.10.3 --verbose --builddir=.stack-work/dist/x86_64-linux/Cabal-1.22.5.0 copy @(stack_COhPD0SUWBs7s1VUFLBNcf:System.Process.Read src/System/Process/Read.hs:269:3)
        ...

[mgsloan]

Note the docs for --no-copy-bins - Enable/disable copying binaries to the local-bin-path. This does not actually invoke the cabal copy command. Instead, it's literally just copying the executables.

To me it seems broken that cabal would modify the inplace files upon cabal copy... So I suppose there is now a usecase for disabling copy?

I think what we really want is to be able to pass --disable-library-stripping in to cabal configure. See also #1342 #1438 #846

For now, you can try this out by modifying https://github.com/commercialhaskell/stack/blob/master/src/Stack/Types/Build.hs#L607