fix(tachyon): repass permission errors on subprocesses to parent / user

These changes enable issues with permissions that happen while using the
'--subprocesses' option on the 'run' method to propagate back, giving
the user an indication of what went wrong. Previously, it would just
silently fail, nut giving the user a hint of what happened wrong.

Signed-off-by: Sofia Donato Ferreira <flowlnlnln@gmail.com>

Author: flowln

Lib/profiling/sampling/__main__.py

@@ -65,6 +65,7 @@ def handle_permission_error():
         main()
     except PermissionError:
         handle_permission_error()
+        sys.exit(1)
     except SamplingUnknownProcessError as err:
         print(f"Tachyon cannot find the process: {err}", file=sys.stderr)
         sys.exit(1)

Lib/profiling/sampling/_child_monitor.py

@@ -237,7 +237,6 @@ def _spawn_profiler_for_child(self, child_pid):
                 cmd,
                 stdin=subprocess.DEVNULL,
                 stdout=subprocess.DEVNULL,
-                stderr=subprocess.DEVNULL,
             )
             with self._lock:
                 if self._stop_event.is_set():