$ git clone -n https://src.fedoraproject.org/rpms/rust-memmem.git /var/lib/mock/f45-build-43232-801/root/chroot_tmpdir/scmroot/rust-memmem
Cloning into '/var/lib/mock/f45-build-43232-801/root/chroot_tmpdir/scmroot/rust-memmem'...
$ git fetch origin a7b80e5eec4daaea407b210684bc3be03c745616:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-memmem
 * [new ref]         a7b80e5eec4daaea407b210684bc3be03c745616 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a7b80e5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild