just updated glibc to 2.23-r1 & the Cmake configure falls over,might not be relevant,
Created attachment 430714 [details] build log for kde-l10n
Created attachment 430716 [details] cmake log output
OK I can see the issue, it happens with LINGUAS="", correct?
https://github.com/gentoo/gentoo/pull/1272
Thanks all. https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=2080edc90dad56abf2bfeb5a66bdfe34dbf78c2d