$ git clone -n https://src.fedoraproject.org/rpms/step.git /var/lib/mock/f42-build-side-1-3503814-45982/root/chroot_tmpdir/scmroot/step
Cloning into '/var/lib/mock/f42-build-side-1-3503814-45982/root/chroot_tmpdir/scmroot/step'...
$ git fetch origin fe6a4b5e35df4f6307eba9f63564c80b15ff8759:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/step
 * [new ref]         fe6a4b5e35df4f6307eba9f63564c80b15ff8759 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fe6a4b5 25.04.0