.no_stdin, .no_stdout, .no_stderr: The respective channel is
redirected to /dev/null.
- .stdout_to_stderr: stdout of the child is redirected to the
- parent's stderr (i.e. *not* to what .err or
- .no_stderr specify).
+ .stdout_to_stderr: stdout of the child is redirected to its
+ stderr. This happens after stderr is itself redirected.
+ So stdout will follow stderr to wherever it is
+ redirected.
To modify the environment of the sub-process, specify an array of
string pointers (NULL terminated) in .env: