GHC version match check seems to be checking the version that Cabal was compiled with

[adamse]

I'm not 100% but it seems that getPackageGhcVersion is actually parsing out the GHC version that cabal-install/Cabal was built with, not the GHC version for the package.

Here's a snippet of the setup-config I have:

Saved package config for shake-0.17.8 written by Cabal-2.4.1.0 using ghc-8.4
<BLAH> exe:shake
<BLAH BLAH> /Users/adam/.stack/programs/x86_64-osx/ghc-8.6.4/bin/ghc

[adamse]

The setup file does contain the same information as ghc --info a bit further along, which includes the GHC version (with all version components).

[adamse]

I see this was already discovered in #33 (comment)

[alexwl]

You are right.

I wrongly assumed that the version of GHC from the header of setup-config is the version of GHC that was used to build the package.

It seems that this assumption may be correct when the GHC is installed by stack (because versions of GHC and Cabal are pinned), but in general, it is wrong.

I've committed the fix: 4ad872a

[adamse]

Thanks for fixing it. You have built an excellent tool here!