$ git clone -n https://src.fedoraproject.org/rpms/cross-gcc.git /var/lib/mock/f41-build-side-1-2935620-35250/root/chroot_tmpdir/scmroot/cross-gcc
Cloning into '/var/lib/mock/f41-build-side-1-2935620-35250/root/chroot_tmpdir/scmroot/cross-gcc'...
$ git fetch origin e1bd94474541d143d175a16f166308d0c7b55aaf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cross-gcc
 * [new ref]         e1bd94474541d143d175a16f166308d0c7b55aaf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e1bd944 fix build using rpm 4.20