$ git clone -n https://src.fedoraproject.org/rpms/rust-as-slice.git /var/lib/mock/f45-build-40185-769/root/chroot_tmpdir/scmroot/rust-as-slice
Cloning into '/var/lib/mock/f45-build-40185-769/root/chroot_tmpdir/scmroot/rust-as-slice'...
$ git fetch origin 3b67bf59b31f8a98d83e2d95845ee0fe85ef9620:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-as-slice
 * [new ref]         3b67bf59b31f8a98d83e2d95845ee0fe85ef9620 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3b67bf5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild