Created attachment 664060 [details] build.log github-cli fails to build (go-1.14.7 and go-1.15.2).
Created attachment 664063 [details] emerge-info.txt
go version 1.12.13 failed, too. however go version 1.15.5 succeeded.
This issue is caused by something in CFLAGS in make.conf.
In particular: -fdiagnostics-color=always