If I add one of the following
include-dirs: C:\Program Files\MySQL\MySQL Server 5.6\include
extra-lib-dirs: C:\Program Files\MySQL\MySQL Server 5.6\lib
in my cabal file, it will fail with errors such as Warning: 'include-dirs: 5.6\include' directory does not exist., which looks like the paths are being split on spaces. I've tried adding double quotes around them, but the same thing happens.
I couldn't really find if there's another syntax for specifying paths like this, and I tried cabal-install 1.18 and 1.22, both with the same effect, which is why I'm opening the issue in the cabal repo itself. I've also tried escaping the spaces with \\, but that didn't seem to help either.