$ git clone -n https://src.fedoraproject.org/rpms/polly.git /var/lib/mock/f42-build-3487024-45834/root/chroot_tmpdir/scmroot/polly
Cloning into '/var/lib/mock/f42-build-3487024-45834/root/chroot_tmpdir/scmroot/polly'...
$ git fetch origin 8b7ab0ee1f624753ab7de5f000c19303538e9333:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/polly
 * [new ref]         8b7ab0ee1f624753ab7de5f000c19303538e9333 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8b7ab0e Merged into llvm package