Ok, figured it out, based on your link, Jonathan, I thought of just running: make clean ./Setup configure ./Setup build ./Setup install WHICH of course imports Distribution.Simple, whereas calling "make blah" on the Makefile will not do the import of Distribution.Simple
I'm glad the link helped. The error message you're seeing is actually in several places in the source. In the case where I've encountered this message, it's generated at the point where the Setup program is about to be compiled by cabal-install for a package with Build-Type: Custom; in this case, extra arguments were passed to cabal to set the GHC package database location, but those arguments failed a sanity check and resulted in the error message you saw. However, if you compile the Setup program by hand and bypass the check, you can still run it with whatever arguments you want and you won't see the error. The workaround I've used is to run "cabal configure" without the extra arguments. This will build the Setup program and then the Setup program can be run with whatever package-database-related arguments caused the error originally. So you may find that you see the error only when there is no preexisting dist/setup/setup program. But, again, I'd want to see how cabal is being invoked by the Makefile. -- Jonathan Daugherty