When I compiled some code this morning I got an error that said that I should edit my cabal file, but I notice that one thing is missing, the path to the cabal file. Having that in the error message would make fixing it a bit easier and faster in that emacs could take me right to the correct cabal file and that I would know for sure which one it was using. I tried filing this as a bug on the stack github repo but they said it is a ghc issue. [1 of 1] Compiling Main ( tests/test.hs, .stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/test/test-tmp/Main.o ) /home/zkessin/Documents/*****/tests/test.hs:17:1: error: Failed to load interface for ‘Control.Lens’ It is a member of the hidden package ‘lens-4.14’. Perhaps you need to add ‘lens’ to the build-depends in your .cabal file. Use -v to see a list of the files searched for. Progress: 1/2 -- While building package ***********-0.1.0.0 using: /home/zkessin/.stack/setup-exe-cache/x86_64-linux/setup-Simple-Cabal-1.24.0.0-ghc-8.0.1 --builddir=.stack-work/dist/x86_64-linux/Cabal-1.24.0.0 build lib:********** test:test --ghc-options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 -- Zach Kessin SquareTarget http://squaretarget.rocks?utm_source=email-sig Twitter: @zkessin https://twitter.com/zkessin Skype: zachkessin