[Discuss-gnuradio] Possible bug: Exception: circular dependency caught in sort_variables

[Murray Thomson]

Hi,

I'm using Ubuntu 16.04 and I installed GNURadio using the PyBombs. My installation path is /home/user/src/gnuradio/default.

In a terminal
address@hidden:~$cd /home/user/src/gnuradio/default
address@hidden:~/src/gnuradio/default$source setup_env.sh
address@hidden:~/src/gnuradio/default$gnuradio-companion

I create a new flowgraph with two variables

1) ID = a

    Value = b

2) ID = b

    Value = a

Creating a circular dependency. When I click OK, The variable dialog doesn't go away. The expected behaviour, I think, it would be for the bottom part of the dialog box to show the problem. For example, if I assign Value=c to the ID=b, the c value doesn't exist and the dialog shows:

Param - Value(value):
    Value "c" cannot be evaluated:
    name 'c' is not defined

However, with the circular dependency, the variable dialog is empty and the exception is raised in the terminal. The dialog can't be cancelled, only closed with the window close button (red X).

Traceback (most recent call last):
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/gui/ActionHandler.py", line 469, in _handle_action
    flow_graph_update()
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/gui/ActionHandler.py", line 113, in flow_graph_update
    fg.update()
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/gui/FlowGraph.py", line 474, in update
    self.rewrite()
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/core/FlowGraph.py", line 221, in rewrite
    self.renew_namespace()
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/core/FlowGraph.py", line 255, in renew_namespace
    for variable in self.get_variables():
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/core/FlowGraph.py", line 91, in get_variables
    return expr_utils.sort_objects(variables, methodcaller('get_id'), methodcaller('get_var_make'))
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/core/utils/expr_utils.py", line 189, in sort_objects
    sorted_ids = sort_variables(id2expr)
  File "/home/user/src/gnuradio/default/lib/python2.7/dist-packages/gnuradio/grc/core/utils/expr_utils.py", line 164, in sort_variables
    raise Exception('circular dependency caught in sort_variables')
Exception: circular dependency caught in sort_variables