mhs fails to compile cpphs when preprocessed by cpphs-hugs

[AlexandreTunstall]

Setting USECPPHS to cpphs-hugs causes the cpphs build to fail with the following error.

mhs: error: "cpphssrc/malcolm-wallace-universe/polyparse-1.12/src/Text/ParserCombinators/Poly/Parser.hs": line 50, col 5: superflous instance binding

In contrast, bootstrapcpphs succeeds when using bin/cpphs built from the pre-existing generated/cpphs.c.

The cpphs-hugs binary comes from the patched Hugs recommended in the README.

Unfortunately, this prevents bootstrapping without pre-generated sources, since the bootstrapcpphs target needs to run cpphs.

[AlexandreTunstall]

With some non-trivial patching, I've managed to get the MicroHs version of cpphs to work under runhugs. When using that version, mhs is able to build cpphs without relying on generated/cpphs.c.

The patches I've written are not yet public, but I plan on publishing them within a week. Ping me if I've forgotten to link them here.

[augustss]

The complaint you got is because MIN_VERSION_base is not defined to some sensible value.