[Discuss-gnuradio] Strange behaviour of example 'variable-config.grc'

[John Coppens]

Hi,

Pardon my newness to gnuradio... I compiled and installed the latest
dev tar.gz. I tried to compile 3.4.2 with autotools, but didn't get
anywhere. So I followed an advice in a mail I found, and, using
cmake/gmake, all went well (no error messages at least).

Impatiently, I composed a small system with a wav-file reader, low-pass,
and audio-output, and this worked fine. More systematically, I tried to
load the example in /gnuradio-examples/grc/simple, called
variable-config.grc. Here I get the error:

Generating: 
"/usr/local/src/hardware/gnuradio/gnuradio-examples/grc/simple/variable_config_demo.py"
Generate Error: circular dependency caught in sort_variables
>>> Failue
Traceback (most recent call last):
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/gui/ActionHandler.py", 
line 291, in _handle_action
    generator.write()
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/python/Generator.py", 
line 66, in write
    open(self.get_file_path(), 'w').write(str(self))
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/python/Generator.py", 
line 102, in __str__
    variables = self._flow_graph.get_variables()
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/python/FlowGraph.py", 
line 101, in get_variables
    return expr_utils.sort_objects(variables, lambda v: v.get_id(), lambda v: 
v.get_var_make())
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/python/expr_utils.py", 
line 148, in sort_objects
    sorted_ids = sort_variables(id2expr)
  File 
"/usr/local/lib64/python2.6/site-packages/gnuradio/grc/python/expr_utils.py", 
line 129, in sort_variables
    if not indep_vars: raise Exception('circular dependency caught in 
sort_variables')
Exception: circular dependency caught in sort_variables

Executing: 
"/usr/local/src/hardware/gnuradio/gnuradio-examples/grc/simple/variable_config_demo.py"


Seemingly randomly, I get a red title in some box, and the error message:

Param - Enabled(_enabled):
        Value "True" cannot be evaluated:
        circular dependency caught in sort_variables

Any suggestions for further testing?

(Python 2.6.6, GNU Radio Companion v3.5.x-xxx-xunknown).
Linux 2.6.37.3 #1 SMP Sun Mar 13 20:31:56 ART 2011 x86_64 AMD Athlon(tm) 64 X2 
Dual Core Processor 3600+ AuthenticAMD GNU/Linux


Greetings,
John