$ git clone -n https://src.fedoraproject.org/rpms/valgrind.git /var/lib/mock/f45-build-37880-718/root/chroot_tmpdir/scmroot/valgrind
Cloning into '/var/lib/mock/f45-build-37880-718/root/chroot_tmpdir/scmroot/valgrind'...
$ git fetch origin a44e0e250a4a4255a40434b36aa091aeaa603736:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/valgrind
 * [new ref]         a44e0e250a4a4255a40434b36aa091aeaa603736 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a44e0e2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild