rqt_graph not working on indigo before doing anything

[asmodehn]

I just did :

alexv@AlexV-Linux:~/Projects$ source /opt/ros/indigo/setup.bash 
alexv@AlexV-Linux:~/Projects$ rqt_graph 
Couldn't import dot_parser, loading of dot files will not be possible.
PluginHandlerDirect._restore_settings() plugin "rqt_graph/RosGraph#0" raised an exception:
Traceback (most recent call last):
  File "/opt/ros/indigo/lib/python2.7/dist-packages/qt_gui/plugin_handler_direct.py", line 116, in _restore_settings
    self._plugin.restore_settings(plugin_settings_plugin, instance_settings_plugin)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_graph/ros_graph.py", line 203, in restore_settings
    self._refresh_rosgraph()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_graph/ros_graph.py", line 227, in _refresh_rosgraph
    self._update_graph_view(self._generate_dotcode())
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_graph/ros_graph.py", line 260, in _update_graph_view
    self._redraw_graph_view()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_graph/ros_graph.py", line 293, in _redraw_graph_view
    same_label_siblings=True)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/qt_dotgraph/dot_to_qt.py", line 234, in dotcode_to_qt_items
    graph = pydot.graph_from_dot_data(dotcode.encode("ascii", "ignore"))
  File "/usr/lib/python2.7/dist-packages/pydot.py", line 220, in graph_from_dot_data
    return dot_parser.parse_dot_data(data)
NameError: global name 'dot_parser' is not defined

So I started digging :

alexv@AlexV-Linux:~/Projects$ python
Python 2.7.6 (default, Oct 26 2016, 20:30:19) 
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pydot
Couldn't import dot_parser, loading of dot files will not be possible.
>>> pydot.__file__
'/usr/lib/python2.7/dist-packages/pydot.pyc'

So in my case pydot in ubuntu trusty doesnt have dot_parser available by default. After a bit of googling I found out that the pyparsing package could be the cause.

alexv@AlexV-Linux:~/Projects$ python
Python 2.7.6 (default, Oct 26 2016, 20:30:19) 
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pyparsins
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named pyparsins
>>> import pyparsing
>>> pyparsing.__file__
'/usr/local/lib/python2.7/dist-packages/pyparsing.pyc'
>>> 
alexv@AlexV-Linux:~/Projects$ sudo pip deinstall pyparsing
ERROR: unknown command "deinstall" - maybe you meant "install"
alexv@AlexV-Linux:~/Projects$ sudo pip duninstall pyparsing
ERROR: unknown command "duninstall" - maybe you meant "uninstall"
alexv@AlexV-Linux:~/Projects$ sudo pip uninstall pyparsing
Uninstalling pyparsing:
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/DESCRIPTION.rst
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/METADATA
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/RECORD
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/WHEEL
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/metadata.json
  /usr/local/lib/python2.7/dist-packages/pyparsing-2.2.0.dist-info/top_level.txt
  /usr/local/lib/python2.7/dist-packages/pyparsing.py
  /usr/local/lib/python2.7/dist-packages/pyparsing.pyc
Proceed (y/n)? y
  Successfully uninstalled pyparsing
alexv@AlexV-Linux:~/Projects$ python
Python 2.7.6 (default, Oct 26 2016, 20:30:19) 
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pydot
>>> pydot.__version__
'1.0.28'
>>> pydot.__file__
'/usr/lib/python2.7/dist-packages/pydot.pyc'

So my recent pyparsing (2.2.0) was not working with my old pydot (1.0.28).

I found a few issues related to that, especially : https://github.com/erocarrera/pydot/issues/81

[asmodehn]

I recently thought about a few other things you need to know :

• There https://github.com/k-okada/break_rqt_graph/blob/master/CMakeLists.txt#L17 you can add pip options to that command line : https://github.com/asmodehn/catkin_pip/blob/devel/cmake/catkin-pip-requirements.cmake.in#L32 this will modify the behavior of how things are installed.

• There is also a CATKIN_PIP_NO_DEPS variable, used like this : https://github.com/asmodehn/catkin_pip/blob/devel/cmake/catkin-pip-package.cmake.in#L100 setup by default to True : https://github.com/asmodehn/catkin_pip/blob/devel/cmake/catkin-pip.cmake.in#L42 since usually one does not want to install dependencies (they should be satisfied either by another ROS package, or on the system). However it is possible to make it easier to port a python package to ROS (in devel space only, in install space dependencies will not be installed from this package)

• Therefore the catkin_pip_requirements command is usually not necessary, if all dependencies are properly specified in the setup.py, and are satisfied by existing system or ros packages.