I were upgrading from dev-libs/libpeas-1.22.0-r1 to dev-libs/libpeas-1.26.0 and got the error /usr/lib64/libpeas-gtk-1.0.so: undefined reference to `peas_gettext' since the package is compiling /usr/lib64/libpeas-gtk-* the version from the work-directory should be linked against, and not the old version from a previous installation on the system! instead I get: linking of temporary binary failed: Command '['x86_64-pc-linux-gnu-gcc', '-pthread', '-o', '/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/tmp-introspectttojem7d/PeasGtk-1.0', '-O2', '-march=native', '-mtune=native', '-fstack-protector-strong', '-fomit-frame-pointer', '-pipe', '/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/tmp-introspectttojem7d/PeasGtk-1.0.o', '-L.', '-Wl,-rpath,.', '-Wl,--no-as-needed', '-L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-Wl,-rpath,/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-L/usr/lib64', '-Wl,-rpath,/usr/lib64', '-L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas-gtk', '-Wl,-rpath,/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas-gtk', '-L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-Wl,-rpath,/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-L/usr/lib64', '-Wl,-rpath,/usr/lib64', '-L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas-gtk', '-Wl,-rpath,/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas-gtk', '-L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-Wl,-rpath,/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas', '-L/usr/lib64', '-Wl,-rpath,/usr/lib64', '-lpeas-gtk-1.0', '-lpeas-1.0', '-lpeas-gtk-1.0', '-lglib-2.0', '-lgobject-2.0', '-lgirepository-1.0', '-lgtk-3', '-lgdk-3', '-lpangocairo-1.0', '-lpango-1.0', '-latk-1.0', '-lcairo-gobject', '-lcairo', '-lgdk_pixbuf-2.0', '-lgio-2.0', '-lgmodule-2.0', '-lgio-2.0', '-lgobject-2.0', '-Wl,--export-dynamic', '-lgmodule-2.0', '-pthread', '-lglib-2.0', '-Wl,-O1', '-Wl,--as-needed']' returned non-zero exit status 1. i.e. there should be no -L/usr/lib64 before -L/var/tmp/portage/dev-libs/libpeas-1.26.0/work/libpeas-1.26.0-build/libpeas-gtk temporary fix: rm -f /usr/lib64/libpeas-* before upgrading, or manually uninstall and install new version, or sandbox it...
I don't see current versions (i.e., v1.26.0) using -L/usr/lib* so I think this is fixed.