Hi, I don't know what a clean build is. But I've been installing LXDE from source these days in Debian Sid.
They have all built fine, the latest code of the cited apps included.
The only exception was when I configured libfm with --enable-gtk-doc but then I'm not sure if that's right as it has already --enable-gtk-doc-html enabled.
Not all have WORKED fine though but that's another issue (bugs were reported to lxsession and lxpanel).
Sorry Martin, posting to the list now.