Fix misleading error summary on compile error (#9674)

I think there's an issue for this somewhere too.

Co-authored-by: hauntsaninja <>

Author: hauntsaninja

mypy/dmypy_server.py

@@ -743,7 +743,7 @@ def pretty_messages(self, messages: List[str], n_sources: int,
                 n_errors, n_files = count_stats(messages)
                 if n_errors:
                     summary = self.formatter.format_error(n_errors, n_files, n_sources,
-                                                          use_color)
+                                                          use_color=use_color)
             else:
                 summary = self.formatter.format_success(n_sources, use_color)
             if summary:

mypy/main.py

@@ -111,11 +111,13 @@ def flush_errors(new_messages: List[str], serious: bool) -> None:
         if messages:
             n_errors, n_files = util.count_stats(messages)
             if n_errors:
-                stdout.write(formatter.format_error(n_errors, n_files, len(sources),
-                                                    options.color_output) + '\n')
+                summary = formatter.format_error(
+                    n_errors, n_files, len(sources), blockers=blockers,
+                    use_color=options.color_output
+                )
+                stdout.write(summary + '\n')
         else:
-            stdout.write(formatter.format_success(len(sources),
-                                                  options.color_output) + '\n')
+            stdout.write(formatter.format_success(len(sources), options.color_output) + '\n')
         stdout.flush()
     if options.fast_exit:
         # Exit without freeing objects -- it's faster.

mypy/util.py

@@ -680,13 +680,20 @@ def format_success(self, n_sources: int, use_color: bool = True) -> str:
             return msg
         return self.style(msg, 'green', bold=True)
 
-    def format_error(self, n_errors: int, n_files: int, n_sources: int,
-                     use_color: bool = True) -> str:
+    def format_error(
+        self, n_errors: int, n_files: int, n_sources: int, *,
+        blockers: bool = False, use_color: bool = True
+    ) -> str:
         """Format a short summary in case of errors."""
-        msg = 'Found {} error{} in {} file{}' \
-              ' (checked {} source file{})'.format(n_errors, 's' if n_errors != 1 else '',
-                                                   n_files, 's' if n_files != 1 else '',
-                                                   n_sources, 's' if n_sources != 1 else '')
+
+        msg = 'Found {} error{} in {} file{}'.format(
+            n_errors, 's' if n_errors != 1 else '',
+            n_files, 's' if n_files != 1 else ''
+        )
+        if blockers:
+            msg += ' (errors prevented further checking)'
+        else:
+            msg += ' (checked {} source file{})'.format(n_sources, 's' if n_sources != 1 else '')
         if not use_color:
             return msg
         return self.style(msg, 'red', bold=True)