Docs tweaks: how to install with macOS Silicon / ARM

[Eric-Arellano]

Hello, thanks for this excellent project!

Would you be open to a PR to tweak the docs to describe how to build with macOS Silicon? There isn't yet a pre-installed Protoc binary released through GitHub releases (protocolbuffers/protobuf#8062), so I had to brew install protobuf. Looks like I didn't actually have to set PROTOC or PROTOC_INCLUDE; protoc being on the $PATH was sufficient iiuc.

I'd be happy to update some docs. Maybe these places?

• The below error message. We can maybe detect if on macOS ARM and if so, append a suggestion to install Protoc, e.g. via brew install protobuf?

Failed to find the protoc binary. The PROTOC environment variable is not set, there is no bundled protoc for this platform, and protoc is not in the PATH

• Maybe somewhere in the README, like https://github.com/danburkert/prost#using-prost-in-a-cargo-project
• https://docs.rs/prost-build/0.7.0/prost_build/index.html#sourcing-protoc

Also, the docs from https://docs.rs/prost-build/0.7.0/prost_build/index.html#sourcing-protoc give an example for how to set Protoc via homebrew, but it looks like Homebrew has (recently?) changed its default install dirs. I'm happy to update this.

PROTOC=/opt/homebrew/bin/protoc
PROTOC_INCLUDE=/opt/homebrew/include

Let me know what would be helpful!

[danburkert]

Are you running prost 0.6 or 0.7? My understanding is that as of #394 prost-build should ‘just work’, and that PR is included in 0.7. Happy to take a pr to update the brew example if it’s no longer accurate.

[danburkert]

Actually it appears the /opt location is specific to arm macs: https://docs.brew.sh/Installation

[Eric-Arellano]

Are you running prost 0.6 or 0.7?

Ah! Indeed, we're using Prost 0.6.1 over at https://github.com/pantsbuild/pants. Sorry I hadn't caught #394 earlier, great to see that included.

Actually it appears the /opt location is specific to arm macs

Interesting, good catch. Thanks! The number of macOS Silicon users is so much lower that it makes sense to stick with the /usr/local path. Lmk if you'd like a tiny PR to clarify in those docs it's for Homebrew on macOS x86.

[Eric-Arellano]

Ah, another possibility for the Homebrew example:

PROTOC=$(brew --prefix)/bin/protoc
PROTOC_INCLUDE=$(brew --prefix)/include

[danburkert]

Ah, another possibility for the Homebrew example:

That's fancy, a PR to that effect would be great!