installation with Cabal fails

[pauloud]

My installation with Cabal failed on Mac OS 10.14 while trying to install Spock, morph building failed with
src/Control/Monad/Trans/Compose.hs:60:7: error: Not in scope: type constructor or class ‘MonadFail’ | 60 | , MonadFail | ^^^^^^^^^
And when I'm trying to intsall only morph I've got a problem with postgresql package

/Users/me/.cabal/logs/ghc-8.6.3/pstgrsql-lbpq-0.9.4.3-198df10e.log
):
[1 of 1] Compiling Main             ( /var/folders/y2/0hb8j18x2mx699f66shljych0000gn/T/cabal-install.-37497/dist-newstyle/tmp/src-37498/postgresql-libpq-0.9.4.3/dist/setup/setup.hs, /var/folders/y2/0hb8j18x2mx699f66shljych0000gn/T/cabal-install.-37497/dist-newstyle/tmp/src-37498/postgresql-libpq-0.9.4.3/dist/setup/Main.o )
Linking /var/folders/y2/0hb8j18x2mx699f66shljych0000gn/T/cabal-install.-37497/dist-newstyle/tmp/src-37498/postgresql-libpq-0.9.4.3/dist/setup/setup ...
Configuring postgresql-libpq-0.9.4.3...
setup: The program 'pg_config' is required but it could not be found.

I don't know wether those two errors have the same cause or not.

[tomferon]

I somehow haven't seen any notification about this issue before but for what it's worth after such a long time, the first error you saw was not about morph but about hackage.haskell.org/package/mmorph (with two m's).