Setup: The program happy is required but it could not be found
Please declare happy as a required build tool.
Doesn't happen with 3.1.3. Alex comes with the Happy-generated files. It sometimes happens that Cabal has a bug where it doesn't include these files in the package, but I think the current package is fine in that respect.
This happened to me too, had to include happy as required build tool to build alex.
this is not supposed to happen. What version of Alex was this?
This was actually for #50, which is one commit ahead of master.