-q suppressing stderr output, but not all of it

[birkenfeld]

This is with cargo 0.11.0 (ca743f3 2016-05-23) and rustc 1.10.0-nightly (764ef92ae 2016-05-19).

The option help (checked cargo build, cargo run) says

-q, --quiet             No output printed to stdout

while most of (all of?) Cargo's messages are printed to stderr.

When using the option, some output is not suppressed, for example the error: Process didn't exit successfully when using cargo run and getting a nonzero exit status.

This makes it unnecessarily hard to use cargo run and capture the output of only the subprocess. (In my case, using target/debug/foo directly is cumbersome because the executable is partially dynamically linked and cargo is doing nice things like setting LD_LIBRARY_PATH correctly for me.)

[alexcrichton]

Yeah currently the shell continues to emit errors whenever it's configured in quiet mode, but this should probably be suppressed for the binary itself for cargo run