catch all exceptions during import of usermodels.py; closes #149

src/gui_qt/fit/fitfunction.py

@@ -6,6 +6,7 @@ from nmreval.configs import config_paths
 from nmreval import models
 from nmreval.lib.importer import find_models
 from nmreval.lib.colors import BaseColor, Tab10
+from nmreval.lib.logger import logger
 from nmreval.utils.text import convert
 
 from ..lib.iconloading import get_icon
@@ -50,8 +51,14 @@ class QFunctionWidget(QtWidgets.QWidget, Ui_Form):
         user_defined = []
         try:
             user_defined = find_models(config_paths() / 'usermodels.py')
-        except FileNotFoundError:
-            pass
+        except Exception as e:
+            import traceback
+            _ = QtWidgets.QMessageBox.warning(
+                self,
+                'No user functions',
+                f'Loading user-defined function failed with exception:\n'
+                f'{"".join(traceback.format_exception(e, limit=1))}')
+            logger.exception("Invalid usermodels.py", exc_info=e)
 
         for model in user_defined:
             name = model.__name__