$ git clone -n https://src.fedoraproject.org/rpms/python-niaarm.git /var/lib/mock/f39-build-1629850-39580/root/chroot_tmpdir/scmroot/python-niaarm
Cloning into '/var/lib/mock/f39-build-1629850-39580/root/chroot_tmpdir/scmroot/python-niaarm'...
$ git fetch origin 8b700fa1baadbca421e0a0c649a7d8d6f0d7da42:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-niaarm
 * [new ref]         8b700fa1baadbca421e0a0c649a7d8d6f0d7da42 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8b700fa Fix dependencies for building docs