$ git clone -n https://src.fedoraproject.org/rpms/rust-unit-prefix.git /var/lib/mock/f45-build-45951-829/root/chroot_tmpdir/scmroot/rust-unit-prefix
Cloning into '/var/lib/mock/f45-build-45951-829/root/chroot_tmpdir/scmroot/rust-unit-prefix'...
$ git fetch origin 415cdd10f55598a39e112529d54a8b94e7474611:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-unit-prefix
 * [new ref]         415cdd10f55598a39e112529d54a8b94e7474611 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 415cdd1 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild