From 2e25222ad0ea127f9d2b5e5d4546503474bfecb6 Mon Sep 17 00:00:00 2001
From: "Michael J. Sullivan" <sully@msully.net>
Date: Wed, 16 May 2018 18:50:44 -0400
Subject: [PATCH] Clean up the traceback from the `run` mode

Don't start the server from inside a catch block, since that produces
and ugly traceback if the server crashes.
---
 mypy/dmypy.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/mypy/dmypy.py b/mypy/dmypy.py
index faf2921060e9..76fcd5a9cc9b 100644
--- a/mypy/dmypy.py
+++ b/mypy/dmypy.py
@@ -212,9 +212,7 @@ def do_run(args: argparse.Namespace) -> None:
     since we don't want to duplicate mypy's huge list of flags.
     (The -- is only necessary if flags are specified.)
     """
-    try:
-        get_status()
-    except BadStatus as err:
+    if not is_running():
         # Bad or missing status file or dead process; good to start.
         start_server(args, allow_sources=True)
 
@@ -441,6 +439,15 @@ def read_status() -> Dict[str, object]:
     return data
 
 
+def is_running() -> bool:
+    """Check if the server is running cleanly"""
+    try:
+        get_status()
+    except BadStatus as err:
+        return False
+    return True
+
+
 # Run main().
 
 if __name__ == '__main__':