$ git clone -n https://src.fedoraproject.org/rpms/rust-pcg-mwc.git /var/lib/mock/f45-build-43692-805/root/chroot_tmpdir/scmroot/rust-pcg-mwc
Cloning into '/var/lib/mock/f45-build-43692-805/root/chroot_tmpdir/scmroot/rust-pcg-mwc'...
$ git fetch origin 9e23560192298a3d0f1a57867c7d51d91becbde5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pcg-mwc
 * [new ref]         9e23560192298a3d0f1a57867c7d51d91becbde5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9e23560 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild