during a workshop I encountered this problem when installing tidal on one laptop which was solved with the help of @Leofltt. This post is for people that will have the same issue in the future.
If you get this error when installing tidal from cabal:
cabal: Failed to build exe:hsc2hs from hsc2hs-0.68.7 (which is required by tidal-1.7.8).
It means your ghc version and your cabal version are not compatible, this can be solved by updating ghc to a newer version.
If you have installed with ghcup type this:
ghcup install ghc 9.0.1
and then after the installation is done:
ghcup set ghc 9.0.1
after setting the appropriate version you should be able to install tidal with
cabal install tidal --lib
Hope this solves your problem if you stumble across this