Closed
Description
Bug report
Bug description:
pdb allows to register an alias without a command.
Calling that alias raises an unhandled exception.
$ /tmp/ cat bar.py
breakpoint()
$ /tmp/ python bar.py
--Return--
> /tmp/bar.py(1)<module>()->None
-> breakpoint()
(Pdb) alias foo
(Pdb) foo
Traceback (most recent call last):
File "/tmp/bar.py", line 1, in <module>
breakpoint()
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/bdb.py", line 94, in trace_dispatch
return self.dispatch_return(frame, arg)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/bdb.py", line 153, in dispatch_return
self.user_return(frame, arg)
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/pdb.py", line 372, in user_return
self.interaction(frame, None)
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/pdb.py", line 435, in interaction
self._cmdloop()
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/pdb.py", line 400, in _cmdloop
self.cmdloop()
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/cmd.py", line 137, in cmdloop
line = self.precmd(line)
^^^^^^^^^^^^^^^^^
File "/home/home/.pyenv/versions/3.11.1/lib/python3.11/pdb.py", line 473, in precmd
while args[0] in self.aliases:
~~~~^^^
IndexError: list index out of rangeThe general syntax of alias foo is valid, as it allows to print the alias. However, if there is no command registered, calling it fails.
I am unsure if raising an exception is the wanted behavior here. I think providing an error message which indicates that the current alias is unknown could be more appropriate, e.g.:
$ python /tmp/bar.py
--Return--
> /tmp/bar.py(1)<module>()->None
-> breakpoint()
(Pdb) alias foo
*** Unkown alias. To create an alias see 'help alias'A solution could be to add an additional check to catch cases where one tries to register an alias without a command.
CPython versions tested on:
3.10, 3.11, CPython main branch
Operating systems tested on:
Linux