$ git clone -n https://src.fedoraproject.org/rpms/rust-same-file.git /var/lib/mock/f45-build-44699-816/root/chroot_tmpdir/scmroot/rust-same-file
Cloning into '/var/lib/mock/f45-build-44699-816/root/chroot_tmpdir/scmroot/rust-same-file'...
$ git fetch origin 7d2ae79a671b742bb2692f82d2d91833d66ca0e1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-same-file
 * [new ref]         7d2ae79a671b742bb2692f82d2d91833d66ca0e1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7d2ae79 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild