not usable as dependency in stack project since it contains a submodule

[jwaldmann]

I want to use this in pure-matchbox (e.g.,) but this is blocked on commercialhaskell/stack#5536

[jwaldmann]

there's other ways to solve this: install kissat (header and library) through your distributions's manager (e.g., Fedora has kissat-devel). That's much better than copying the C sources into the cabal sdist (the minisat library on hackage does this)