$ git clone -n https://src.fedoraproject.org/rpms/rust-trybuild2.git /var/lib/mock/f45-build-45760-827/root/chroot_tmpdir/scmroot/rust-trybuild2
Cloning into '/var/lib/mock/f45-build-45760-827/root/chroot_tmpdir/scmroot/rust-trybuild2'...
$ git fetch origin 229a0caccaa46ef913c48f7772a7b791989bb700:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-trybuild2
 * [new ref]         229a0caccaa46ef913c48f7772a7b791989bb700 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 229a0ca Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild