I guess this is wanted by many testers and packagers. Today I took some time and write a very comprehensive detailed guide for building, setting up, and debugging pcmanfm/libfm.
Testers or packagers please refer to this document. I think the page is enough for solving most of the FAQ. Please tell me if it isn’t.
Here is the guide: http://wiki.lxde.org/en/PCManFM_build_and_setup_guide