Error: No supported platform for closure-compiler found.

[Maribeth Moffatt]

Hello,

I'm on the Blockly team which has used closure compiler for a long time. Recently, we've noticed that we get the above error every couple of weeks/months and we have to update to the latest version of closure-compiler to resolve. We can't figure out what's going on, does anyone have any insight? Of course it would be great if we stayed up to date but it's not ideal for our CI to break unexpectedly every few weeks.

Details:

- We use closure compiler through the npm distribution and the gulp plugin

- Things work locally but break in CI

- Our CI uses github-hosted Ubuntu runners

- We've considered falling back to the Java option but we'd have to install Java on the github runners which would slow down our CI

- Example of failing run: https://github.com/RaspberryPiFoundation/blockly/actions/runs/23859860952/job/69563257149?pr=9675 (expand the `build` section of the `run` step to see the error)
- link to gulp script where we invoke closure compiler: https://github.com/maribethb/blockly/blob/5dedd858725c5925b13278a278783fad7c958a6d/packages/blockly/scripts/gulpfiles/build_tasks.mjs#L525

Only theory I have: GitHub updates their runner every week, maybe they're updating it in a way that makes it incompatible with older versions of the native linux compiler? But I compared the runner details from a failing and a passing run and they appear the same in both, so I'm not sure that's it:

Current runner version: '2.333.1' Runner Image Provisioner Operating System Ubuntu 24.04.4 LTS Runner Image Image: ubuntu-24.04 Version: 20260323.65.1

Happy to provide more details if that would help. Haven't found references to this particular error message anywhere else.

Thanks,
Maribeth