$ git clone -n https://src.fedoraproject.org/rpms/rust-cxxbridge-macro.git /var/lib/mock/f40-build-2270764-54854/root/chroot_tmpdir/scmroot/rust-cxxbridge-macro
Cloning into '/var/lib/mock/f40-build-2270764-54854/root/chroot_tmpdir/scmroot/rust-cxxbridge-macro'...
$ git fetch origin 0c4139723e5c270f58491d9877e56ea5fcb52f5c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cxxbridge-macro
 * [new ref]         0c4139723e5c270f58491d9877e56ea5fcb52f5c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0c41397 Update to version 1.0.115 (rhbz#2257016)