Error for workflow file with ~6000-element matrix: "Maximum object size exceeded". What is the maximum object size?

[runeksvendsen]

Select Topic Area

Question

Body

The following run throws an error due to too many items in the package element inside jobs.<job_name>.strategy.matrix: https://github.com/runeksvendsen/all-hackage-ghc-pkg/actions/runs/9234137911: Error when evaluating 'strategy' for job 'nix-build'. Maximum object size exceeded.

I would like to avoid this error by splitting up the matrix, but to do that I need to know what the maximum object size is.
It would be probably be a good idea to include this number in the actual error message, so it error itself makes it clear how it can be avoided.

[ChristopherHX]

You would also exceed maximum matrix job count of ca. 256, and bypassing this limit via reusable workflows used to trigger an abuse protection that disables GitHub Actions on your account.

Reference:
https://docs.github.com/en/actions/using-jobs/using-a-matrix-for-your-jobs#using-a-matrix-strategy

[runeksvendsen]

@ChristopherHX thanks. Yes, I found a report of this happening so I will be careful: https://github.com/orgs/community/discussions/38704.

I do think it's annoying that GitHub isn't clear about its limits. The docs you link clearly states that each matrix can generate at most 256 jobs, but what if my workflow file contains two different jobs that each uses a 256-element matrix? That's 512 jobs, which doesn't appear to exceed any stated limit.

I think GitHub should be clear about its limits (is it just max 256 jobs per matrix or 256 jobs per workflow that's the limit?), and possibly enforce them — ie. do not allow me to create more than 256 jobs per workflow if you think I shouldn't be allowed to.
The correct solution to someone exceeding a limit they shouldn't be allowed to exceed is to prevent them and others from doing so in the future; not punishing them.

[github-actions[bot]]

🕒 Discussion Activity Reminder 🕒

This Discussion has been labeled as dormant by an automated system for having no activity in the last 60 days. Please consider one the following actions:

1️⃣ Close as Out of Date: If the topic is no longer relevant, close the Discussion as out of date at the bottom of the page.

2️⃣ Provide More Information: Share additional details or context — or let the community know if you've found a solution on your own.

3️⃣ Mark a Reply as Answer: If your question has been answered by a reply, mark the most helpful reply as the solution.

Note: This dormant notification will only apply to Discussions with the Question label. To learn more, see our recent announcement.

Thank you for helping bring this Discussion to a resolution! 💬