The Tor Project is switching to Rust

Why not Go? It's more portable.

Don't Rust and Go build to mostly-statically-compiled binaries? (With the exception of a link to libc.) (This isn't a rhetorical question, this is something I don't know a lot about

I'd imagine the biggest cultural reason is that many Rust developers were C developers who had a reason to find something better, but still scoff at garbage collection, large runtimes, etc. They probably have a lot more Rust expertise in their circle.

Another technical reason is that they were trying to replace their C code with Rust in bits and pieces before they went with a full rewrite. I don't know about Go, but this is something ergonomically doable in Rust.

Rust can create statically-compiled binaries on Linux by using musl instead of glibc, but it’s not the default like it is in Go and is as a result not quite as effortless. There are a lot of crates with native dependencies that require slight environment tweaks to work on a musl build. Go on the other hand goes to great lengths to not need to link to any C code at all, to the point of shipping its own default TLS library and cryptographic primitives.

I thought the default for both Rust and Go were to statically compile everything except the dynamic link to libc? And that you could optionally statically include musl with a bit of extra work.

I've never had to do anything unusual with building, but I thought the "almost-ststically-compiled" thing was somewhere Go and Rust were almost identical.