darwin build

[thehajime]

This is yet another mac build PR. darwin support of containerd is still underway, but would like to ask your opnions.

There are several notes on the current status:

• On amd64 darwin, this patch can do nerdctl run with --net=none option; with --net options, it won't work. On arm64/darwin, nerdctl itself works, but there is no available runtime.
• go.mod tentatively put a commit hash which is not the upstreamed contaienrd; I will update this PR to non-draft one once Extend mount package on macOS to use external snapshotters containerd#5935 is finalized.
• cross build for darwin requires osxcross (https://github.com/tpoechtrager/osxcross) because dependent package (i.e., moby/sys) needs CGO_ENABLED.

This might be a duplicate of #645

[AkihiroSuda]

Not sure about legal status of this.
Better not to use it, probably.

[AkihiroSuda]

We can just compile it on macOS instances of GHA

[thehajime]

Not sure about legal status of this.
Better not to use it, probably.

indeed..

We can just compile it on macOS instances of GHA

I see.
if we don't have to publish the binaries via make artifacts over cross compiling on a Linux host, it should be okay.

I will seek a way to handle this.

[AkihiroSuda]

This has to be marked as an experimental feature in docs/experimental.md.
We also need a well written document, perhaps in docs/darwin.md, or docs/lkl.md.
Differences from lima nerdctl should be explained in the docs, too.

[thehajime]

This has to be marked as an experimental feature in docs/experimental.md.
We also need a well written document, perhaps in docs/darwin.md, or docs/lkl.md.
Differences from lima nerdctl should be explained in the docs, too.

okay. I'll also prepare documents to address the above concerns.

[apostasie]

@thehajime curious if this is still something people want to pursue.

[AkihiroSuda]

It is still nice to support Darwin hosts, especially for Wasm and VM runtimes

[slonopotamus]

See #3763 for a new attempt.