ACTIONS_RUNTIME_URL, ACTIONS_RUNTIME_TOKEN and ACTIONS_CACHE_URL environment variables are missing.

[quisse]

Github actions have undocumented environment variables named ACTIONS_RUNTIME_URL, ACTIONS_RUNTIME_TOKEN and ACTIONS_CACHE_URL. The actions/cache action relies on this to create the url to interact with for storing caches.
https://github.com/actions/toolkit/blob/1cc56db0ff126f4d65aeb83798852e02a2c180c3/packages/cache/src/internal/cacheHttpClient.ts#L33-L47

They all get populated over here

This is the cause of #285, #169 is linked.

[github-actions]

Issue is stale and will be closed in 7 days unless there is new activity

[quisse]

The issue is still persistent afaik.

[DivoK]

Any news about this problem? Came here from #285

[ayozemr]

Coming from #169

[jshwi]

Hi, I'm trying to understand the problem. Are these values dynamically set? Can they be manually set and read by act? If so what to?

[catthehacker]

Are these values dynamically set?

@jshwi Those environmental variables are only available to GitHub Actions runners, whether it be runner hosted by GitHub or self-hosted one.

Can they be manually set and read by act?

Probably.

If so what to?

No one knows, if it was that easy it would be fixed already.

Perhaps guys from GitHub (@joshmgross from https://github.com/actions/cache or @TingluoHuang from https://github.com/actions/runner, top committers) could chime in here, maybe give us some clues on how we could solve that issue.
I presume it won't be so easy as obtaining and just hardcoding those values since, most likely they are undocumented for a reason and the reason is it's supposed to work only on GitHub Actions service (but please, prove me wrong).
There is artefacts API https://docs.github.com/en/rest/reference/actions#artifacts which could be used to replace artefacts actions but I've not found anything regarding cache.