Gentoo's Bugzilla –
Attachment 608568 Details for
Bug 707330dev-libs/libgcrypt-1.9.4 : .../work/libgcrypt-1.8.5/random/jitterentropy-base.c:60:4: error: #error "The CPU Jitter random number generator must not be compiled with optimizations. See documentation. Use the compiler switch -O0 for compiling jitterentr...