From 6b1960d811d25e8f754324259a5b4fd59f8f8162 2016-10-25 12:36:39
From: Thomas Kluyver <thomas@kluyver.me.uk>
Date: 2016-10-25 12:36:39
Subject: [PATCH] Remove debugger curframe attribute before using checkline()

Closes gh-10028

---

diff --git a/IPython/core/magics/execution.py b/IPython/core/magics/execution.py
index 36a3645..78a0372 100644
--- a/IPython/core/magics/execution.py
+++ b/IPython/core/magics/execution.py
@@ -816,6 +816,11 @@ python-profiler package from non-free.""")
             self.shell.InteractiveTB.pdb = self.shell.InteractiveTB.debugger_cls()
             deb = self.shell.InteractiveTB.pdb
 
+        # deb.checkline() fails if deb.curframe exists but is None; it can
+        # handle it not existing. https://github.com/ipython/ipython/issues/10028
+        if hasattr(deb, 'curframe'):
+            del deb.curframe
+
         # reset Breakpoint state, which is moronically kept
         # in a class
         bdb.Breakpoint.next = 1