Test process::tests::test_inherit_env fails when environment variable contains non-ascii characters

[anta0]

Result of ./x.py test src/libstd/:

failures:

---- process::tests::test_inherit_env stdout ----
        thread 'process::tests::test_inherit_env' panicked at 'called `Result::unwrap()` on an `Err` value: FromUtf8Error { bytes: [82, 85, 83, ... <snip> ... ], error: Utf8Error { valid_up_to: 2674 } }', src\libcore\result.rs:860

My environment variable contains "ChocolateyLastPathUpdate=水 12 14 19:40:40 2016" and which is the cause of this.

• Rust version: current HEAD.
• Host: x86_64-pc-windows-gnu

Note: Environment variables are OsStr but output encoding of cmd /c set depends on the environment (ShiftJIS on my computer).

[petrochenkov]

Duplicate of #25268
The solution is to change the console code page to UTF-8 before running tests:

cmd /c "chcp 65001"

The old build system issued a warning for this specific case, but it was lost in rustbuild.

[Mark-Simulacrum]

I've been working on a rework of compiletest that fixes the underlying cause, but I'm going to close this since we do warn to change the code page as @petrochenkov notes above today I believe.