There's a comment in the TODO file for xfce4-settings-4.7.3 that I heartily endorse. And feel it's worth adding as a bug to gain visibility. Mouse Settings (Nick) ------------------------------------------------------------------------ * Try to make inputproto 1.4.0 and libxi 1.2.0 optionnal. Solaris, at least, doesn't ship with inputproto as a package. Although it does ship the header files. I can fake this manually by just creating a fake inputproto.pc file, but really the check, if any, should be for the header files themselves rather than the package. So, on Solaris, I simply delete the inputproto check completely as a workaround.
Not a good idea. The .pc files are there for a good reason and make library detection rock solid from the Xfce-side, even as a fallback.