Most mysterious bug ever.

Expected:

• dockerized --shell <command> -c env should print the current environment

Actual:

• In some specific conditions, there is no output from the container at all, and dockerized just exits.

  Run bin/dockerized -v --shell perl -c env | tee ~/shell.log
  Dockerized root: /home/runner/work/dockerized/dockerized
  Loading: '/home/runner/work/dockerized/dockerized/.env'
  Compose files: /home/runner/work/dockerized/dockerized/docker-compose.yml
  Setting up shell in container for perl...
  Entrypoint: [/bin/bash]
  Command:    [-c env]
  Preparing compose environment...
  Network dockerized_default  Creating
  Network dockerized_default  Created
  Volume "dockerized_node_modules"  Creating
  Volume "dockerized_node_modules"  Created
  Volume "dockerized_python_modules"  Creating
  Volume "dockerized_python_modules"  Created
  Volume "dockerized_pip_cache"  Creating
  Volume "dockerized_pip_cache"  Created
  Volume "dockerized_go_cache"  Creating
  Volume "dockerized_go_cache"  Created
  Volume "dockerized_home"  Creating
  Volume "dockerized_home"  Created
  Running one-off container...
  Container exited with code 0.
  

Observations:

• These shell tests worked perfectly in march, and suddenly broke.
• Many official docker images were updated under the same tags. Alpine and busybox were changed.
• Affected commands:
  • go, python, perl, rustc
• Still works perfectly locally on windows
• It only breaks the first time. Running the command twice makes it work somehow.
• Running docker-compose before dockerized also causes the --shell test to work.
• For some commands, the issue is with bash. Switching to sh for --shell fixes the bug.
• sh is not a universal fix. rustc uses sh and still doesn't work.
• Was able to reproduce once on local Ubuntu VM. Cannot reproduce after. Even docker system prune -af won't help to reproduce it, running without a tty. (true | dockerized --shell perl -c env | cat)
• docker-compose run --rm <command> always seems to work.

Hypothese (and motivation):

• Something related to setting up the networks / compose project
  • There could be small implementation differences between docker-compose run and dockerized
  • Since docker-compose seems to work without failure, there must be something different causing the bug.
• Something TTY related
  • Github Actions have no TTY whereas local running from a shell will provide a TTY, explaining reproduction difficulty
  • ❌ Then why does it work the second time?
  • Running echo helloworld the first time didn't fix perl, but disabling TTY did. So TTY is involved.
• Related to updates in Bash and Alpine in official docker images
  • This did work a month ago and suddenly broke. Re-ran an old successful action and it didn't work anymore.
  • Specifying the exact alpine version in the docker image tag has fixed the issue for some commands. Unfortunately, the old digests are not published by dockerhub, so it's not possible to restore all commands. Also, this is not a good long term solution.
  • ❌ Then why does it work the second time?
• Something specifically related to the env command

Excluded causes:

• Related to pulling the images the first time.
  • ❌ Added dockerized --pull. Running this before the shell test doesn't make a difference.
• Related to a race condition in creating the network.
  • ❌ The issue occurs consistently with a specific subset of commands and is not unpredictable