$ git clone -n https://src.fedoraproject.org/rpms/rust-rmp.git /var/lib/mock/f45-build-44465-813/root/chroot_tmpdir/scmroot/rust-rmp
Cloning into '/var/lib/mock/f45-build-44465-813/root/chroot_tmpdir/scmroot/rust-rmp'...
$ git fetch origin 5cf9ae443fa2d232a7a3070c02fa4976e2d39e2d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rmp
 * [new ref]         5cf9ae443fa2d232a7a3070c02fa4976e2d39e2d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5cf9ae4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild