$ git clone -n https://src.fedoraproject.org/rpms/cross-gcc.git /var/lib/mock/f41-build-side-1-3133766-39700/root/chroot_tmpdir/scmroot/cross-gcc
Cloning into '/var/lib/mock/f41-build-side-1-3133766-39700/root/chroot_tmpdir/scmroot/cross-gcc'...
$ git fetch origin b39505102c271def7e78fafa40a5b00e7480db1f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cross-gcc
 * [new ref]         b39505102c271def7e78fafa40a5b00e7480db1f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b395051 Update to 14.2.1