When reproducing issue24160 in IDLE, I saw this traceback:
Traceback (most recent call last):
  File "<pyshell#14>", line 1, in <module>
    pdb.run("reload(test3)")
  File "C:\Python27\lib\pdb.py", line 1238, in run
    Pdb().run(statement, globals, locals)
  File "C:\Python27\lib\bdb.py", line 400, in run
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
  File "test3.py", line 1, in <module>
    [contents of test3.py]
  File "C:\Python27\lib\bdb.py", line 51, in trace_dispatch
    return self.dispatch_call(frame, arg)
  File "C:\Python27\lib\bdb.py", line 80, in dispatch_call
    self.user_call(frame, arg)
  File "C:\Python27\lib\pdb.py", line 148, in user_call
    self.interaction(frame, None)
  File "C:\Python27\lib\pdb.py", line 210, in interaction
    self.cmdloop()
  File "C:\Python27\lib\cmd.py", line 142, in cmdloop
    stop = self.onecmd(line)
  File "C:\Python27\lib\pdb.py", line 279, in onecmd
    return cmd.Cmd.onecmd(self, line)
  File "C:\Python27\lib\cmd.py", line 221, in onecmd
    return func(arg)
  File "C:\Python27\lib\pdb.py", line 622, in do_clear
    err = self.clear_bpbynumber(i)
KeyError: 'c:\\documents and settings\\perry\\desktop\\coding_projects\\python\\test3.py'

Reproducing the same bug in the standard interpreter produces a more detailed traceback:
Traceback (most recent call last):
  File "<pyshell#592>", line 1, in <module>
    pdb.run("reload(test3)")
  File "C:\Python27\lib\pdb.py", line 1238, in run
    Pdb().run(statement, globals, locals)
  File "C:\Python27\lib\bdb.py", line 400, in run
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
  File "test3.py", line 1, in <module>
    foo = 7789
  File "C:\Python27\lib\bdb.py", line 51, in trace_dispatch
    return self.dispatch_call(frame, arg)
  File "C:\Python27\lib\bdb.py", line 80, in dispatch_call
    self.user_call(frame, arg)
  File "C:\Python27\lib\pdb.py", line 148, in user_call
    self.interaction(frame, None)
  File "C:\Python27\lib\pdb.py", line 210, in interaction
    self.cmdloop()
  File "C:\Python27\lib\cmd.py", line 142, in cmdloop
    stop = self.onecmd(line)
  File "C:\Python27\lib\pdb.py", line 279, in onecmd
    return cmd.Cmd.onecmd(self, line)
  File "C:\Python27\lib\cmd.py", line 221, in onecmd
    return func(arg)
  File "C:\Python27\lib\pdb.py", line 622, in do_clear
    err = self.clear_bpbynumber(i)
  File "C:\Python27\lib\bdb.py", line 297, in clear_bpbynumber
    self._prune_breaks(bp.file, bp.line)
  File "C:\Python27\lib\bdb.py", line 268, in _prune_breaks
    self.breaks[filename].remove(lineno)
KeyError: 'c:\\documents and settings\\perry\\desktop\\coding_projects\\python\\test3.py'

The actual error message is irrelevant, other than the fact that in the standard interpreter, the traceback contains two more entries.