cabal.out

# cabal check
Warning: The following errors will cause portability problems on other environments:
Warning: Unfortunately the language extensions 'MonoPatBinds' break the parser in earlier Cabal versions so you need to specify 'cabal-version: >= 1.4'. Alternatively if you require compatibility with earlier Cabal versions then you may be able to use an equivalent compiler-specific flag.
Warning: Hackage would reject this package.