Docker: Chrome "tab crashed" from small /dev/shm causes false test failures (e.g. accessibility statement reported missing)

[marcusosterberg]

URL

https://www.akassanvision.se

Webperf_core version

2026.5.3

What environment are you running?

• Using GitHub Actions
• Using Docker Image from Dock Hub
• Local machine
• Other, please describe your environment in How to reproduce.

Has anyone else reported it already?

• No, there are no other issues related to this in Issues.

Expected Behavior

The page loads and the statement is rated on its merits.

Actual Behavior.

When running the public Docker image without an increased --shm-size, Chrome's
renderer crashes (tab crashed) on heavier pages and the page load times out.
The test then falls back to a false result. For test 26 (accessibility statement)
this reports an existing statement as missing (critical).

It also produces a contradictory score: Overall 2.48 vs A11y 1.0, because the
network warning and the not-applicable sub-checks dilute the overall rating while
a11y reflects the (false) critical failure.

fixed by larger shm:
docker run --rm --shm-size=2g webperfse/webperf-core
python3 default.py -t 26 -u https://www.akassanvision.se -r

Overall: 4.0
A11y: 4.0
- Accessibility statement, compatible word is missing (error)
- Accessibility statement, no evaluation method specified (error)

How to reproduce

docker run --rm webperfse/webperf-core \
      python3 default.py -t 26 -u https://www.akassanvision.se -r

Log output

[7h3Rabbit]

@marcusosterberg what should be done? maybe it should be documented better that you need to set it in our documentation?
It is mentioned already at https://github.com/Webperf-se/webperf_core/blob/main/docs/getting-started-docker.md BUT it is not clear that you HAVE to use it and there are no clear instructions of recommendation of at least 4 GB.

[7h3Rabbit]

@marcusosterberg please note that we have used commands like this in regression tests for a loooooong time:
docker run --shm-size=4g -e MAX_OLD_SPACE_SIZE=3000 webperfse/webperf-core:test python default.py -t 30 -r -i defaults/sites.json