mpgtx has some problems: prestripping, does not use LDFLAGS, does not use CHOST-CXX. I attach a patch to fix all problems
Created attachment 103644 [details, diff] mpgtx-1.3.1.ebuild patch
Created attachment 103645 [details, diff] files/mpgtx-1.3.1-configure.patch
Commited as ~arch -r1, thanks :) I also added another patch to not force cxxflags to -O3, rather use user defined cxxflags.