Build mgd on macOS in a GH action

[david-crespo]

WIP, just experimenting

[david-crespo]

First problem: need to give it access to dendrite, which is a private repo.

Updating crates.io index
    Updating git repository `https://github.com/oxidecomputer/falcon`
From https://github.com/oxidecomputer/falcon
 * [new ref]         a223368cbb036279b3ddc1c803ce5a0219440204 -> refs/commit/a223368cbb036279b3ddc1c803ce5a0219440204
    Updating git repository `[https://github.com/oxidecomputer/dendrite`](https://github.com/oxidecomputer/dendrite%60)
fatal: could not read Username for 'https://github.com/': Device not configured
error: failed to get `common` as a dependency of package `ddm v0.1.0 (/Users/runner/work/maghemite/maghemite/ddm)`

Caused by:
  failed to load source for dependency `common`

Caused by:
  Unable to update https://github.com/oxidecomputer/dendrite?branch=main#eaec4213

Caused by:
  failed to clone into: /Users/runner/.cargo/git/db/dendrite-627b239a911c6241

Caused by:
  process didn't exit successfully: `git fetch --tags --force --update-head-ok 'https://github.com/oxidecomputer/dendrite' '+refs/heads/*:refs/remotes/origin/*' '+HEAD:refs/remotes/origin/HEAD'` (exit status: 128)
Error: Process completed with exit code 101.

[jclulow]

FWIW, it hopefully won't be that much work to get buildomat for Mac working. I have an M2 system set up in the lab and I have had some basic success creating VMs on it with tart and the Cirrus Labs Mac OS X images. Just a little more plumbing to do to get something that works, I reckon. Then you'll be able to get the same private repository access as the existing buildomat jobs, etc.

[david-crespo]

Great! I had also concluded the GH action version is not worth further effort.