[debug mode] Disable parallelism

corrscope/corrscope.py

@@ -688,7 +688,7 @@ class CorrScope:
             for shmem in all_shmems:
                 shmem.unlink()
 
-        parallelism = self.arg.parallelism
+        parallelism = False  # incompatible with debug plots
         with self._load_outputs():
             if parallelism and parallelism.parallel:
                 play_parallel(parallelism.max_render_cores)

corrscope/gui/view_mainwindow.py

@@ -495,6 +495,7 @@ class MainWindow(QWidget):
         self.action_parallel = create_element(
             QAction, MainWindow, text=tr("&Multi-Core Rendering"), checkable=True
         )
+        self.action_parallel.setDisabled(True)
         self.action_open_config_dir = create_element(
             QAction, MainWindow, text=tr("Open &Config Folder")
         )