Function posix_rewrite 

pub fn posix_rewrite(command: &str, escaped_label: &str) -> String

Build the POSIX form of a rewritten command that carries its exit status to sqz. escaped_label must already be shell-escaped. The newline before ) ends a trailing comment or heredoc. The 2>&1 sits on the group, so a redirect of the command’s own, such as 2>/dev/null or 2> err.log, still wins.