Gentoo's Bugzilla –
Attachment 855360 Details for
Bug 898552sys-apps/utempter-0.5.5.6-r1 fails to compile (MUSL-CLANG-SYSTEM): utempter.c:161:5: error: call to undeclared function gettimeofday; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]