vabal finds a version of GHC that is compatible with the constraints imposed on base package found in the cabal file analyzed. It then uses ghcup to obtain the correct version of the compiler (potentially downloading it). It supports three modes: vabal configure (it configures your project to use the obtained ghc), vabal (it prints to stdout options to give to cabal to use the obtained ghc. Options are escaped so that they can sent to the xargs POSIX utility). vabal show (it works like vabal but prints the version of the obtained ghc to stdout instead of options to pass to cabal). See the README for more detailed informations.