$ git clone -n https://src.fedoraproject.org/rpms/rust-rfc6979.git /var/lib/mock/f39-build-1508799-35410/root/chroot_tmpdir/scmroot/rust-rfc6979
Cloning into '/var/lib/mock/f39-build-1508799-35410/root/chroot_tmpdir/scmroot/rust-rfc6979'...
$ git fetch origin 528563b391cebff7e6a1124e54a45972f93486c0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rfc6979
 * [new ref]         528563b391cebff7e6a1124e54a45972f93486c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 528563b Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild