$ git clone -n https://src.fedoraproject.org/rpms/rust-impls.git /var/lib/mock/f45-build-42532-794/root/chroot_tmpdir/scmroot/rust-impls
Cloning into '/var/lib/mock/f45-build-42532-794/root/chroot_tmpdir/scmroot/rust-impls'...
$ git fetch origin 62af07417e5b91c34ba534e1bd3537966cfeddf0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-impls
 * [new ref]         62af07417e5b91c34ba534e1bd3537966cfeddf0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 62af074 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild