$ git clone -n https://src.fedoraproject.org/rpms/rust-headers.git /var/lib/mock/f45-build-42302-792/root/chroot_tmpdir/scmroot/rust-headers
Cloning into '/var/lib/mock/f45-build-42302-792/root/chroot_tmpdir/scmroot/rust-headers'...
$ git fetch origin 8d4f3fb16f990ddc1f9d9dbf03530be8d9030aa3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-headers
 * [new ref]         8d4f3fb16f990ddc1f9d9dbf03530be8d9030aa3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8d4f3fb Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild