Gentoo's Bugzilla –
Attachment 656206 Details for
Bug 730542app-emulation/gallium-nine-standalone-0.5: /usr/lib/gcc/x86_64-pc-linux-gnu/9.3.0/../../../../x86_64-pc-linux-gnu/bin/ld: /usr/lib64/libX11.so: error adding symbols: file in wrong format collect2: error: ld returned 1 exit status