in fuzz python process, inherit stderr so we can see python errors

fuzz/fuzz.rs

@@ -21,6 +21,7 @@ pub unsafe extern "C" fn LLVMFuzzerTestOneInput(input: *const u8, len: usize) ->
         let mut proc = Command::new("atom.py")
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
+            .stderr(Stdio::inherit())
             .spawn()
             .expect("failed to spawn atom.py");