I'm resorting my various libraries into a single directory, mostly because of the way visual studio now allows users to add directories, but also partly because of the discussion we had about depreciating the LIB_TAG option. However, when I do so, and when I specify this directory using -DCMAKE_LIBRARY_PATH the Agg library is not found. Checking the findAGG module it seems rather complex by comparison to e.g. findFreetype. It seems that AGG is not being found because on windows PKG_CONFIG_EXECUTABLE is false, so the variable _AGGLinkFlags isn't set and findAGG therefore doesn't ever look for the library. Commenting out the if(_AGGLinkFlags) line allows AGG to be found correctly.
Is there any need for all the pkgconfig