Cache not working on macOS

[rsubtil]

Today the CI started failing for macOS systems. I need to obtain a MacOS SDK from a macOS instance, and then pass it to an Ubuntu instance for cross-compilling libraries.

For that I used cache: I firstly extract the MacOS SDK and upload it to a cache directory. The Ubuntu instance then receives that cache and can start compilling.

This worked without issue a few months ago, but as of today it doesn't. It looks like the macOS instances are successfully uploading the cache as it reports a 51MB size:

And the cache is being received on the Ubuntu instance, also reporting that 51MB size:

However, the cached files never appear (it should be MacOSX12.3.sdk.tar.xz):

Here's one such failed run. And the CI file is available here.

I've tried:

• Evicting this cache many times to force it's regeneration; issue persists
• Switching the Ubuntu image to a macOS instance to check if there's issues between different OSes (because of #591); issue persists
• Caching an empty test file instead; the file also doesn't appear
• Updating from cache@v3 to latest cache@v3.0.10; issue persists

The cache is working on the other system builds (Windows and Linux) which run exclusively on Ubuntu instances, however. If this is an issue with the macOS runner itself, I can move the issue there.

[rsubtil]

Seems like the paths work differently. From what I've gathered, macOS starts with ~ (/Users/runner), while Linux starts on project work dir (e.g. /home/runner/work/retrohub/retrohub).

I claimed this worked before but it's likely I had an old cache that was created using artifacts. Because it got evicted it now had a mismatch on paths.

Either way, it's solved, so I'll close this.