$ git clone -n https://src.fedoraproject.org/rpms/rkcommon.git /var/lib/mock/f38-build-side-42-init-devel-953669-28786/root/chroot_tmpdir/scmroot/rkcommon
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-953669-28786/root/chroot_tmpdir/scmroot/rkcommon'...
$ git fetch origin e17bfac2b4093ee60f699925d95c60ee8e1f6a5a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rkcommon
 * [new ref]         e17bfac2b4093ee60f699925d95c60ee8e1f6a5a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e17bfac supports x86 and ARM 64bit arches for now