升级期间，我执行了 cd /var/discourse; git pull; ./launcher rebuild app。
系统显示“升级完成”和“POSTGRES 升级完成”。后者提示“再次重建”，但这似乎没有任何作用。
尽管升级已完成，但我无法启动应用。执行 ./launcher start app 时出现以下错误：
Unable to find image 'local_discourse/app:latest' locally
/usr/bin/docker: Error response from daemon: pull access denied for local_discourse/app, repository does not exist or may require 'docker login'.
See '/usr/bin/docker run --help'.
无法再次重启应用，且不确定该如何继续。
./discourse-doctor 也无济于事（它仅检测到应用未运行，尝试重建并重启，最终仍出现相同错误）。
由于是新用户，无法附加文件，以下是我认为来自调试日志的相关片段：
Failed to rebuild app.
Checking your domain name . . .
Connection to community.gingkoapp.com succeeded.
You should probably remove any non-standard plugins and rebuild.
Attempting to restart existing container. . .
+ /usr/bin/docker run --shm-size=512m -d --restart=always -e LANG=en_US.UTF-8 -e RAILS_ENV=production -e UNICORN_WORKERS=2 -e UNICORN_SIDEKIQS=1 -e RUBY_GLOBAL_METHOD_CACHE_SIZE=131072 -e RUBY_GC_HEAP_GROWTH_MAX_SLOTS=40000 -e RUBY_GC_HEAP_INIT_SLOTS=400000 -e RUBY_GC_HEAP_OLDOBJECT_LIMIT_FACTOR=1.5 -e DISCOURSE_DB_SOCKET=/var/run/postgresql -e DISCOURSE_DB_HOST= -e DISCOURSE_DB_PORT= -e DISCOURSE_DEVELOPER_EMAILS=REDACTED -e DISCOURSE_HOSTNAME=community.gingkoapp.com -e DISCOURSE_SMTP_ADDRESS=smtp.mailgun.org -e DISCOURSE_SMTP_USER_NAME=postmaster@community.gingkoapp.com -e DISCOURSE_SMTP_PASSWORD=REDACTED -h community-app -e DOCKER_HOST_IP=172.17.0.1 --name app -t -p 80:80 -p 2222:22 -v /var/discourse/shared/standalone:/shared -v /var/discourse/shared/standalone/log/var-log:/var/log --mac-address 02:fc:04:ee:f5:11 local_discourse/app /sbin/boot
Unable to find image 'local_discourse/app:latest' locally
/usr/bin/docker: Error response from daemon: pull access denied for local_discourse/app, repository does not exist or may require 'docker login'.
See '/usr/bin/docker run --help'.
Failed to restart the container.
