$ git clone -n https://src.fedoraproject.org/rpms/python-idna.git /var/lib/mock/f40-build-2203556-51928/root/chroot_tmpdir/scmroot/python-idna
Cloning into '/var/lib/mock/f40-build-2203556-51928/root/chroot_tmpdir/scmroot/python-idna'...
$ git fetch origin 7b798b5aea1faf26d0bd0d6b9050c71cd8cbe869:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-idna
 * [new ref]         7b798b5aea1faf26d0bd0d6b9050c71cd8cbe869 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7b798b5 Update to 3.6 (rhbz#2251399)