$ git clone -n https://src.fedoraproject.org/rpms/centpkg.git /var/lib/mock/f41-build-side-1-3126706-39525/root/chroot_tmpdir/scmroot/centpkg
Cloning into '/var/lib/mock/f41-build-side-1-3126706-39525/root/chroot_tmpdir/scmroot/centpkg'...
$ git fetch origin b7adb6619f76d5a65828bdd63b34b4e3cf30007a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/centpkg
 * [new ref]         b7adb6619f76d5a65828bdd63b34b4e3cf30007a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b7adb66 Update to 0.9.1