Allow ghcup to compile cabal-install from source like hls and ghc
The other day I tried to install the latest commit of cabal-install on my system, and tried to do ghcup compile cabal --git-ref master --ghc 9.2.4
, but ghcup doesn't know how to do that (yet).
I would certainly help the cabal team a lot when we advertise new features to be tested ahead of time.