Expand description

Assert a command stderr string is equal to an expression.

Pseudocode:
(command ⇒ stderr ⇒ string) = (expr into string)

§Example

use std::process::Command;

let mut command = Command::new("bin/printf-stderr");
command.args(["%s", "hello"]);
let s = String::from("hello");
assert_command_stderr_eq_expr!(command, s);

§Module macros