Gentoo's Bugzilla –
Attachment 844653 Details for
Bug 887877[guru] sci-electronics/dsview-1.3.0 fails to compile (CLANG-STRICTER-SYSTEM): strutil.c:345:12: error: call to undeclared function strcasecmp; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]