Incorrect detection on Debian/Buster

[kinnison]

I set about installing rustup onto a Debian/buster system and saw the following:

somniloquy% curl https://sh.rustup.rs/ | sh                                    
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 10652  100 10652    0     0  60522      0 --:--:-- --:--:-- --:--:-- 60522
info: downloading installer
Warning: Detected OS X platform older than 10.13
Warning: Not forcing TLS v1.2, this is potentially less secure

Welcome to Rust!

This will download and install the official compiler for the Rust programming 
language, and its package manager, Cargo.
…

Seems we're incorrectly identifying Debian as OS-X somehow?

[Rudi3]

Is it possible that you have an alias or similar to sw_vers?
What is the output of command -v sw_vers? (https://github.com/rust-lang/rustup.rs/blob/9864b0b95e98ccdbe5bde3c5bded2dd95b9d18ad/rustup-init.sh#L410)
To eliminate that, actually using the _arch variable from get_architecture to check for darwin may work. I can't test this on darwin, but I might do a PR to fix that soon.

[kinnison]

Is it possible that you have an alias or similar to sw_vers?

Looks like I had somehow gained a fake sw_vers on my path, possibly for testing something meant for Darwin. This bug is not a bug. Well spotted.