rustdoc: consider running tests in a fresh temporary directory

[pnkfelix]

Spawned off of Issue #13965. I had a couple nice illustrative bits of code that spewed output into some files. I didn't really think about the consequences of doing that with respect to the rustdoc workflow.

( What, doesn't everyone do their builds in an isolated build tree? No, not everyone? Wait, is it just me? :) ... )

Anyway, I guess this is a feature request that either rustdoc itself or our make infrastructure should ensure that the current working directory is set to a separate workspace when rustdoc runs, and the contents of that workspace should be deleted if rustdoc terminates without an error condition.

[steveklabnik]

Triage: I am not aware of any change here.

[Mark-Simulacrum]

I believe this is fixed today:

rust/src/librustdoc/test.rs

Line 241 in bc9822a

let outdir = Mutex::new(TempDir::new("rustdoctest").ok().expect("rustdoc needs a tempdir"));

.