Hi, On Thu, 10 Jun 2021 at 10:47, Philip Munksgaard wrote: > Setup.hs:3:1: error: > Could not find module ‘Distribution.Extra.Doctest’ > Perhaps you meant Distribution.Simple.Doctest (from Cabal-2.4.0.1) > Use -v to see a list of the files searched for. > | > 3 | import Distribution.Extra.Doctest (defaultMainWithDoctests) > | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ I have not investigated more but I guess the issue is from the new package ghc-cabal-doctest which is probably poorly configured. All the best, simon