$MAMBA_EXE not in $PATH on macos-latest runners

[mattwthompson]

On macOS, the executable is installed into /Users/runner/micromamba-bin/micromamba, which is not in $PATH on macos-latest (M1 runners) but is on macos-12 (Intel architecture). This appears to be the root cause of surprising behavior i.e. commands like which micromamba fail. Here is a reproducing workflow: https://github.com/mattwthompson/micromamba-path-reproduction/actions/runs/10891923866/workflow

Credit to @ethanholz for trying a bunch of things that resulted in narrowing this down.

We can work around this by setting micromamba-binary-path but this doesn't seem like it should be required. In fact, I didn't have to set this option in the past. This behavior changed sometime around Friday of last week (9/13 or 9/14) for reasons I'm unable to pin down:

• Runner image changes seem minimal to me: https://github.com/actions/runner-images/pull/10603/files
• No recent releases of this action (this commit from May is referenced: f8b8a1e)
• No recent releases of mamba itself (1.5.9 is used)

Am I doing something wrong here? Was I doing something wrong before?

[pavelzw]

xref actions/runner-images#10624, prefix-dev/setup-pixi#139

[mattwthompson]

Ah thanks! I figured it was probably a more widespread issue and was surprised it hadn't been reported here earlier today. Quite messy

[pavelzw]

Seems to be fixed upstream.