DRONE_RUNNER_LABELS not work

agent can be assigned job

drone-agent(env.yaml)
DRONE_RUNNER_LABELS=xxx:yyy

gitlab(.drone.yml)
node:
 xxx: yyy

drone version:

commit 8329de0af39f954a693321383cd56a8e9d467903
Merge: 8738099 9304750
Author: Brad Rydzewski <brad.rydzewski@gmail.com>
Date:   Thu Oct 31 00:14:10 2019 -0700

    Merge remote-tracking branch 'origin/master'