$ git clone -n https://src.fedoraproject.org/rpms/libportal.git /var/lib/mock/f39-build-1558067-37302/root/chroot_tmpdir/scmroot/libportal
Cloning into '/var/lib/mock/f39-build-1558067-37302/root/chroot_tmpdir/scmroot/libportal'...
$ git fetch origin 401a1f6f29439881b14df7e50e7367e580242a9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libportal
 * [new ref]         401a1f6f29439881b14df7e50e7367e580242a9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 401a1f6 Update to 0.7.1