From 20d68dfcc07bd389ce2ea7b0773c44d97ebeb68d Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Tue, 17 Apr 2018 13:38:27 +0200
Subject: [PATCH] pdb.do_debug: handle any exceptions

This avoids crashing with e.g. `debug foo(` (which causes a
SyntaxError).
---
 Lib/pdb.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/pdb.py b/Lib/pdb.py
index 60bdb7675c81316..caa27416b424a15 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -1096,7 +1096,10 @@ def do_debug(self, arg):
         p = Pdb(self.completekey, self.stdin, self.stdout)
         p.prompt = "(%s) " % self.prompt.strip()
         self.message("ENTERING RECURSIVE DEBUGGER")
-        sys.call_tracing(p.run, (arg, globals, locals))
+        try:
+            sys.call_tracing(p.run, (arg, globals, locals))
+        except Exception as exc:
+            print('Failed to run cmd: %r' % exc)
         self.message("LEAVING RECURSIVE DEBUGGER")
         sys.settrace(self.trace_dispatch)
         self.lastcmd = p.lastcmd