$ git clone -n https://src.fedoraproject.org/rpms/centpkg.git /var/lib/mock/f40-build-1466833-23714/root/chroot_tmpdir/scmroot/centpkg
Cloning into '/var/lib/mock/f40-build-1466833-23714/root/chroot_tmpdir/scmroot/centpkg'...
$ git fetch origin f2ef50adb0984c5815244eba2183920d5efc4110:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/centpkg
 * [new ref]         f2ef50adb0984c5815244eba2183920d5efc4110 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f2ef50a Tweak autodetection of repo name. (CS-2340)