Resource temporarily unavailable not so temporarily stopping compilation

[Havvy]

Trying to compile mdbook with Rust 1.22.1 while downloading a game, I get this error at some random crate every time. Checking the master source, I don't think it would change if I used 1.24.0. Since the error is from a temporarily unavailable resource, it should just be retried?

thread '<unnamed>' panicked at 'failed to acquire jobserver token: Resource temporarily unavailable (os error 11)', src/librustc_trans/back/write.rs:1619:28

error: failed to acquire jobserver token: Resource temporarily unavailable (os error 11)

I'm getting this when running on NixOS (Linux distro) in a VirtualBox VM, if that helps any.

[Havvy]

Where panic is produced:

rust/src/librustc_trans/back/write.rs

Line 1777 in efda9ba

let msg = &format!("failed to acquire jobserver token: {}", e);

What actually creates the Err, I'm not sure.

[Havvy]

I'm getting this consistently now (but on different crates) if anybody wants to give me advice for providing more information.

[Havvy]

Dupe of #46981