Run strace -f -eexecve go build to see whats going on under the covers. The filenames are because 6c and 6g both produced an object file named hello.6. 6g,6c,

Run strace -f -eexecve go build to see whats going on under the covers. The filenames are because 6c and 6g both produced an object file named hello.6. 6g,6c, and 6a produce object files on amd64. 6l is the linker which combines them. Honestly I had a little trouble running the commands individually so I just used go build.