Incorrect parsing when executing %debug print('m n')

[vbraun]

II ran into this issue with a more complicated command and distilled it to this testcase. Other print commands, for example %debug print('mn') without the space can be debugged. Also, any other function instead of print yields the same result:

$ sage -ipython
Python 2.7.8 (default, Feb 15 2015, 03:39:19) 
Type "copyright", "credits" or "license" for more information.

IPython 3.0.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: %debug print('m n')
NOTE: Enter 'c' at the ipdb>  prompt to continue execution.
---------------------------------------------------------------------------
SyntaxError                               Traceback (most recent call last)
SyntaxError: EOL while scanning string literal (<string>, line 1)

[takluyver]

I think this is the collision of Python-style and shell style syntax. You can work around it by quoting the statement: %debug "print('m n')". It should be fixable, though, because %timeit print('m n') is OK.