$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_ignored.git /var/lib/mock/f45-build-44858-818/root/chroot_tmpdir/scmroot/rust-serde_ignored
Cloning into '/var/lib/mock/f45-build-44858-818/root/chroot_tmpdir/scmroot/rust-serde_ignored'...
$ git fetch origin 637c398c48aa508a10f7c6b3816a4e36d2134c7d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_ignored
 * [new ref]         637c398c48aa508a10f7c6b3816a4e36d2134c7d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 637c398 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild