$ git clone -n https://src.fedoraproject.org/rpms/rust-crc64.git /var/lib/mock/f45-build-41056-779/root/chroot_tmpdir/scmroot/rust-crc64
Cloning into '/var/lib/mock/f45-build-41056-779/root/chroot_tmpdir/scmroot/rust-crc64'...
$ git fetch origin c6b93cff96f0ab589914bda102a777e10d140ca9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-crc64
 * [new ref]         c6b93cff96f0ab589914bda102a777e10d140ca9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c6b93cf Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild