$ git clone -n https://src.fedoraproject.org/rpms/k3b.git /var/lib/mock/f38-build-side-42-init-devel-636274-26382/root/chroot_tmpdir/scmroot/k3b
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-636274-26382/root/chroot_tmpdir/scmroot/k3b'...
$ git fetch origin 5bf6c8caf215d854da1c75fd83befb10f56fef19:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/k3b
 * [new ref]         5bf6c8caf215d854da1c75fd83befb10f56fef19 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5bf6c8c Rebuilt for libmpcdec 1.3.0