cargo build doesn't work when in a directory with a non-UTF8 path

[huonw]

[package]

name = "test"
version = "0.0.0"
authors = []

[[lib]]

name = "test"

with src/test.rs empty.

If this is in a valid UTF-8 directory, then cargo build works flawlessly. If this is in an invalid UTF-8 directory (creatable by, e.g., mkdir $(echo -e '\xff') in Bash), then cargo build is rather upset:

  Compiling test v0.0.0 (file:/home/huon/projects/test-rust/�)
error: could not write output: Error opening output file '/home/huon/projects/test-rust/�/target/test.o': No such file or directory
Could not execute process `rustc src/test.rs --crate-type lib --out-dir /home/huon/projects/test-rust/�/target -L /home/huon/projects/test-rust/�/target -L /home/huon/projects/test-rust/�/target/deps` (status=101)

[SimonSapin]

This looks like something using Path::display for something other than displaying.

[alexcrichton]

Closing, #238 handles the cargo side of things and rust-lang/rust#15890 handles what should be the rest.