Executing force:lightning:test:run from Docker container results in Unknown Error (13)

[forcedotcom]

Executing force:lightning:test:run from Docker container results in Unknown Error (13)

[esalman-sfdc]

I am guessing that such an error could either be due to domain resolution issues (e.g. network firewalls/proxies) or due to web-driver config issues (e.g. inability to launch a browser properly
in an environment) which seems more likely based on the error message.

One of the community members had reported similar (not same) error on Travis but they were able to get around it by copying relevant pieces from .travis.yml file of the repo to their repo,

export DISPLAY=:99.0
sh -e /etc/init.d/xvfb start
sleep 3 # give xvfb some time to start

Wondering if you need something similar given this repo uses Travis/CircleCI environments to showcase CI flow and those are headless environments as well :)

By the way, the command also allows some additional webdriver controls via "-f" option. See,
#28

[esalman-sfdc]

Cross Posting (for future visitors):
Possible answer for this question shared here by another user.