Issue warning if performance report cannot be produced

Author: vkarak

reframe/frontend/cli.py

@@ -1592,10 +1592,13 @@ def module_unuse(*paths):
                     data = reporting.performance_compare(
                         rt.get_option('general/0/perf_report_spec'), report
                     )
-                except errors.ReframeError as err:
+                except Exception as err:
                     printer.warning(
                         f'failed to generate performance report: {err}'
                     )
+                    printer.verbose(
+                        ''.join(traceback.format_exception(*sys.exc_info()))
+                    )
                 else:
                     printer.performance_report(data)
 
@@ -1637,6 +1640,9 @@ def module_unuse(*paths):
                     printer.warning(
                         f'failed to store results in the database: {e}'
                     )
+                    printer.verbose(
+                        ''.join(traceback.format_exception(*sys.exc_info()))
+                    )
                 else:
                     printer.info('Current session stored with UUID: '
                                  f'{sess_uuid}')