$ git clone -n https://src.fedoraproject.org/rpms/helix.git /var/lib/mock/f42-build-3532483-46326/root/chroot_tmpdir/scmroot/helix
Cloning into '/var/lib/mock/f42-build-3532483-46326/root/chroot_tmpdir/scmroot/helix'...
$ git fetch origin d857a416aa5bef9ed7ae62c549bde1690393d6e7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/helix
 * [new ref]         d857a416aa5bef9ed7ae62c549bde1690393d6e7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d857a41 Bump pulldown-cmark to 0.13