stack build package:lib still builds exes

[mitchellwrosen]

Reproducible example: https://github.com/mitchellwrosen/stack-issue

Here, the executable has a compiler error but the library does not.

Expected output of stack build stack-issue:lib: (successful build)

Actual output of stack build stack-issue:lib:

stack-issue-0.0.0: build
Preprocessing library stack-issue-0.0.0...
In-place registering stack-issue-0.0.0...
Preprocessing executable 'exe' for stack-issue-0.0.0...
[1 of 1] Compiling Main             ( Main.hs, .stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/exe/exe-tmp/Main.o )

/home/mitchell/junk/stack-issue/Main.hs:3:1:
    Parse error: naked expression at top level
    Perhaps you intended to use TemplateHaskell

--  While building package stack-issue-0.0.0 using:
      /home/mitchell/.stack/setup-exe-cache/x86_64-linux/setup-Simple-Cabal-1.22.5.0-ghc-7.10.3 --builddir=.stack-work/dist/x86_64-linux/Cabal-1.22.5.0 build lib:stack-issue exe:exe --ghc-options " -ddump-hi -ddump-to-file"
    Process exited with code: ExitFailure 1

[sjakobi]

Thanks for the example project! 👍

This is a known and long-standing issue, so I'm closing this a duplicate.

A PR to fix this would be most welcome! :)