$ git clone -n https://src.fedoraproject.org/rpms/rust-macro_rules_attribute.git /var/lib/mock/f45-build-43107-800/root/chroot_tmpdir/scmroot/rust-macro_rules_attribute
Cloning into '/var/lib/mock/f45-build-43107-800/root/chroot_tmpdir/scmroot/rust-macro_rules_attribute'...
$ git fetch origin fe579b338c43da8a54a9945d91829ee86eadf5e3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-macro_rules_attribute
 * [new ref]         fe579b338c43da8a54a9945d91829ee86eadf5e3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fe579b3 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild