I've never seen anyone try to attempt that on Linux. The issue on windows, is you cannot link the debug/release C runtimes into the same project. As far as I know, linux does not have this issue, so there is no problem with accidentally linking to a debug library on linux - hence no need for any _d prefix. The worst that happens on linux is usually just larger library size, and perhaps a bit of slowdown - not really relevant for OIS as it is not doing very much calculations where the slow down would matter.
If you are insistent on really building two different builds of OIS, you should just install it to a different path.. then you could also point pkgconfig to find the other path during certain builds.
