Apple Silicon support

[RunicMoose]

As seen from the latest canary build back in October, the itch app should soon be able to be compiled for native support for arm64 since it is running with electron 11.5.0.

Why hasn't a build for this shown up yet? Or at least instructions on how to compile it for arm64?

[aycyang]

I've tried building the itch app on my M1 Mac, and it... almost works. The window appears but fails at setup because it doesn't know which build of butler to download from itch's download server (https://broth.itch.ovh) and indeed they're not serving an arm64 build of butler there yet. When I patch it to use an x86 build of butler, it seems to work.

In theory, an ARM build of butler would be straightforward for them to produce, since butler is built in Go, and Go is great at cross-compiling. However, looking around at the binaries available, I don't see any that are built for ARM, so I'm guessing they haven't updated their CI/CD for that yet.

[aycyang]

I opened a PR to prepare for whenever arm64 builds of butler and itch-setup become available: #2928

[duffn]

I've opened a PR to add an arm64 build of butler: itchio/butler#267