export LINGUAS="ru"
./configure
make

ends up with:

Making all in po
make[2]: Entering directory `/var/tmp/portage/xfce-extra/thunar-vcs-plugin-0.1.4/work/thunar-vcs-plugin-0.1.4/po'
make[2]: *** No rule to make target `ru.gmo', needed by `all-yes'.  Stop.
make[2]: Leaving directory `/var/tmp/portage/xfce-extra/thunar-vcs-plugin-0.1.4/work/thunar-vcs-plugin-0.1.4/po'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/xfce-extra/thunar-vcs-plugin-0.1.4/work/thunar-vcs-plugin-0.1.4'
make: *** [all] Error 2

because XDT_I18N in configure.ac lists "ru" but the file ru.po is missing from directory po/

this is due to the bad LINGUAS file in git that shouldn't be there...

see also bug 8033 (has same issue, just for reference)