`cargo nm` output includes compiler messages

[spookyvision]

expected: I only get nm output when redirecting/piping cargo nm standard output
actual: rustc/cargo output is included as well:

❯ cargo nm | head -11
    Finished dev [unoptimized + debuginfo] target(s) in 0.00s
warning: unused variable: `unused`
  --> src/main.rs:17:9
   |
17 |     let unused = 4;
   |         ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: 1 warning emitted

0000000100031d88 s GCC_except_table0

[Emilgardis]

cargo-binutils/src/lib.rs

Line 382 in 891939d

let output = lltool.stderr(Stdio::inherit()).output()?;