rustc hangs forever, using 100% CPU, when building rust from source and when running cargo

[jbg]

I’m using a clean installation of macOS Sierra beta 2. In case it matters, I have two Xcode toolchains installed and therefore two clang versions – the current stable Xcode 7.3 and the Xcode 8.0 beta. I tried each operation below once with each toolchain selected using xcode-select; there was no difference.

I tried to get started with Rust this afternoon without much luck.

First I tried to build it from source with brew install rust but after six hours of waiting for the compulation step to complete, with rustc using 100% CPU (on a current-model MacBook Pro, with brew doctor showing no issues other than the beta macOS warning), I decided that maybe I should download a binary package, so I downloaded the current 64-bit Mac OS X .pkg from rust-lang.org and installed this successfully.

Then I tried to start my first project with cargo new mylib --lib. It has hung for 30 minutes so far (top shows rustc using 100% CPU) and I don’t think it’s about to complete.

If I run rustc --version from the command line, I get:

macbook-pro% rustc --version
rustc(75943,0x7fffa5a1c3c0) malloc: *** malloc_zone_unregister() failed for 0x7fffa5a13548

… and it proceeds to use 100% CPU until I kill it.

[TimNN]

Dupe of #34674 I believe, which has been fixed just today by #34719 (the fix should be available in the next nightly).

[alexcrichton]

Indeed!

[jbg]

thanks!

[bosmacs]

This appears to remain a problem in 10.12 beta 6, at least when installing from homebrew; both 1.11 and --HEAD.