message: Pass --color=always through cargo-miri
diff: @@ -945,7 +945,14 @@ fn phase_runner(binary: &Path, binary_args: env::Args, phase: RunnerPhase) {
  // Drop this argument.
  } else if let Some(suffix) = arg.strip_prefix(json_flag) {
  assert!(suffix.starts_with('='));
  - // Drop this argument.
  + // This is how we pass through --color=always. We detect that Cargo is detecting rustc
  + // to emit the diagnostic structure that Cargo would consume from rustc to emit colored
  + // diagnostics, and ask rustc to emit them.
  + // See https://github.com/rust-lang/miri/issues/2037
  + if arg.split(',').any(|a| a == "diagnostic-rendered-ansi") {
  + cmd.arg("--color=always");
  + }
  + // But aside from remembering that colored output was requested, drop this argument.
  } else {
  cmd.arg(arg);
  }
  