$ git clone -n https://src.fedoraproject.org/flatpaks/massif-visualizer /var/tmp/koji/tasks/7900/131827900/massif-visualizer
Cloning into '/var/tmp/koji/tasks/7900/131827900/massif-visualizer'...
$ git fetch origin bbdd62499770a3e375a4c5ad894d03c45a120d45:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/flatpaks/massif-visualizer
 * [new ref]         bbdd62499770a3e375a4c5ad894d03c45a120d45 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bbdd624 F42