Portage currently only looks in a fixed set of directories [/opt/*/lib /lib /usr/lib /usr/X11R6/lib, and the -32 and -64 variants thereof] for shared libraries, static libraries, and libtool scripts. Attached is a patch that searches all of "${D}" for them, but falls back gracefully when the used tools do not (yet) exist on the root. Reproducible: Always Steps to Reproduce:
Created attachment 152911 [details, diff] patch to search harder for libs
Created attachment 152913 [details, diff] the real one this time oops - submitted the wrong file...
Had a quick look over your patch. Why is there a version with find and one without inside?