Gentoo's Bugzilla –
Attachment 863671 Details for
Bug 908253media-sound/ardour[-cpu_flags_x86_sse]: sse_functions_avx_linux.cc:337:17: error: ‘x86_sse_mix_buffers_with_gain’ was not declared in this scope; did you mean ‘x86_sse_avx_mix_buffers_with_gain’?