Thanks for the suggestions: Imants: There is library build-depends: base ==4.6.* (The cabal file was generated by cabal init and so I would hope it's legit :)) I installed Haskell on my Ubuntu just by doing sudo apt-get install haskell-platform. Interestingly, if I do use ghc-mod on a real file with some errors in I get unnecessarily verbose error messages similar to described here: http://mail.haskell.org/pipermail/beginners/2015-February/014573.html I wonder if the issues are related somehow? Norbert: I’m not sure what exactly you are suggesting but if I even take the version constraint out of the cabal file so I have build-depends: base (without any version specified) then I get the same issue. From: Beginners [mailto:beginners-bounces@haskell.org] On Behalf Of Norbert Melzer Sent: 23 June 2015 17:49 To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell Subject: Re: [Haskell-beginners] ghc-mod and cabal "could not find module Prelude" Just add base as dependency in the version constraints matching that base that is delivered with your version of GHC. Alan Buxton <alanbuxton@gmail.com <mailto:alanbuxton@gmail.com> > schrieb am Di., 23.06.2015, 16:48: Hi I’ve recently set up a new Haskell working environment on Ubuntu 14.04. I installed the Ubuntu packaged version of Haskell platform. My problem is that I can’t now get ghc-mod check to work if there is a cabal file in the current directory. I am using: * ghc-mod 5.2.1.2 compiled by GHC 7.6.3 * cabal 1.16.0.2 See below an extract of trying to run ghc-mod check in a directory that was empty until I just ran cabal init in it: ~/tmp-ghc-mod$ ls Setup.hs tmp-ghc-mod.cabal ~/tmp-ghc-mod$ ghc-mod check Setup.hs Setup.hs:1:1:Could not find module `Prelude'It is a member of the hidden package `base'.Perhaps you need to add `base' to the build-depends in your .cabal file.It is a member of the hidden package `haskell98-2.0.0.2'.Perhaps you need to add `haskell98' to the build-depends in your .cabal file.It is a member of the hidden package `haskell2010-1.1.1.0'.Perhaps you need to add `haskell2010' to the build-depends in your .cabal file.Use -v to see a list of the files searched for. ~/tmp-ghc-mod$ mv tmp-ghc-mod.cabal tmp-ghc-mod.cabal.NOT ~/tmp-ghc-mod$ ls dist Setup.hs tmp-ghc-mod.cabal.NOT ~/tmp-ghc-mod$ ghc-mod check Setup.hs Setup.hs:2:1:Warning: Top-level binding with no type signature: main :: IO () ~/tmp-ghc-mod$ So… ghc-mod behaves as expected when there is no cabal file, but doesn’t behave as expected if there is a cabal file. My google fu isn’t helping me out on this: the only issues I have seen are to do with a change in format of the cabal file in newer versions of cabal. Any ideas? Thanks Alan _______________________________________________ Beginners mailing list Beginners@haskell.org <mailto:Beginners@haskell.org> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners