I'm trying to install 'hspec' on my WSL (Windows subsystem for Linux) system. But I fail; see below. For some reason cabal complains about installing a library. (That seems peculiar - isn't that what cabal is for?) But it helpfully suggests adding -lib. Alas, cabal then crashes outright, which should never happen. So I'm stuck. What should I do? Thanks Simon simonpj@MSRC-9870733:~$ cabal --version cabal-install version 3.0.0.0 compiled using version 3.0.0.0 of the Cabal library simonpj@MSRC-9870733:~$ cabal install hspec Resolving dependencies... Up to date Warning: You asked to install executables, but there are no executables in target: hspec. Perhaps you want to use --lib to install libraries instead. simonpj@MSRC-9870733:~$ cabal install --lib hspec Resolving dependencies... Up to date Distribution/Simple/GHC.hs:1959:5-56: Irrefutable pattern failed for pattern Just ghcPkgProg simonpj@MSRC-9870733:~$ which ghc /opt/ghc/bin/ghc simonpj@MSRC-9870733:~$ which ghc-pkg /opt/ghc/bin/ghc-pkg simonpj@MSRC-9870733:~$