ghc-8.8.1 release tarball requires alex at ./configure time
GHC release tarballs used not to require alex
or happy
and included generated versions of parser and lexer.
ghc-8.8.1
release tarball seems to be different and fails ./configure
step:
./configure
...
checking for happy... no
checking for version of happy...
checking for alex... no
checking for version of alex...
configure: error: Alex version 3.1.7 or later is required to compile GHC.