Github-hosted runners for OSX no longer carry a bundled conda installation

[jaimergp]

See https://github.com/conda/conda-standalone/actions/runs/8796238715/job/24143815312?pr=67.

macos-latest runners will now default to macOS 14, which means they run on ARM64 Apple Silicon, not Intel! This breaks the assumption of macos-latest == x86_64. Just a heads up!

We should document this.

The current recommendation is to pin directly to macos-13 to ensure you get an Intel runner. Make sure you are using setup-miniconda@v3.

[jaimergp]

For now, the easiest mitigation to go back to Intel is to use the macos-13 runners. However these will be eventually deprecated.

[jaimergp]

We should maybe install latest Miniconda if $CONDA is not found in a Github-hosted runner to maintain previous behavior. Self-hosted behavior should not be modified, though.

Ah wait, we are doing that already in 3.0.3: #336

[mattwthompson]

I'm a bit lost here

macos-latest runners will now default to macOS 14

Is this change live? The blog says it'll happen at some point in the next 12 weeks from April 1, but no updates there. This page indicates it's already happened to macos-latest and to get x86 we need to call out macos-13?

[jaimergp]

Yes, I'm observing it in some repos already. See the linked CI run above.

[mattwthompson]

Must have happened overnight? Wonder if there'll be an announcement today then

[mattwthompson]

I'm not seeing this change live: https://github.com/mattwthompson/gha-sandbox/actions/runs/8803326872/job/24161162575#step:3:5

[jaimergp]

Yep, you got macos-12 there (check first step). This will take 12 weeks, and we are currently starting the 4th-ish. It might hit you latee, but it will 😁