How can I resolve PyCallGraphException: The command "dot -Tpng -failed with error code 256 error?

Question

Trying to run the following command to make graph of calls using pycallgraph -

pycallgraph graphviz --output-file=/var/www/html/Reports/winmain.png -- token_check.py

But I am getting following error when I run the command.

pycallgraph.exceptions.PyCallGraphException: The command "dot -Tpng -o/var/www/html/Reports/winmain.png /tmp/tmpVDYnvE" failed with error code 256.

Note that I have both 'dot' & graphviz. Can anyone tell how can I resolve this issue?

This is the complete traceback-

Traceback (most recent call last):
File "/usr/bin/pycallgraph", line 26, in <module>
exec(__file_content)
File "/usr/lib/python2.7/site-packages/pycallgraph/pycallgraph.py", line   38, in __exit__
self.done()
File "/usr/lib/python2.7/site-packages/pycallgraph/pycallgraph.py", line 81, in done
self.stop()
File "/usr/lib/python2.7/site-packages/pycallgraph/pycallgraph.py", line 90, in generate
output.done()
File "/usr/lib/python2.7/site-packages/pycallgraph/output/graphviz.py", line 112, in done
'code %(ret)i.' % locals())
 pycallgraph.exceptions.PyCallGraphException: The command "dot -Tpng -o/var/www/html/Reports/winmain.png /tmp/tmpVDYnvE" failed with error code 256.

Also, please can you include the whole Traceback for the following problem. — Kyrylo, Mar 02 '18 at 14:48
Yes. See [this](https://github.com/gak/pycallgraph/issues/100). — Kyrylo, Mar 02 '18 at 14:51
Thank you @Kyrylo But unfortunately it didn't help. I have installed both from pip. — Mr. Sigma., Mar 02 '18 at 14:54
Sorry, I was out of my computer. Can you try to set `output file` into your home folder? Maybe some problems in permissions under `/var/www/...` folder — Kyrylo, Mar 02 '18 at 18:05
Try in terminal `dot -Tpng -o/var/www/html/Reports/winmain.png /tmp/tmpVDYnvE`. Then you might want to create those folders that are not there. — Bishwas Mishra, Feb 26 '19 at 06:44

score -1 · Answer 1 · answered Nov 06 '20 at 04:50

-1

This worked for me

Go to /usr/lib/python2.7/site-packages/pycallgraph/output/graphviz.py

Add a space between -o and the argument. That is ,

Change around line 102

cmd = '{} -T{} -o{} {}'.format(
            self.tool, self.output_type, self.output_file, temp_name
        )

to

cmd = '{} -T{} -o {} {}'.format(
            self.tool, self.output_type, self.output_file, temp_name
        )

answered Nov 06 '20 at 04:50

Loner

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Did not fix it for me. My run command is: `pycallgraph graphviz -- run.py` – Under-qualified NASA Intern Feb 20 '22 at 23:43
In such a case, you have to add another space between `-T` and the argument. But the error persists – Palinuro Jul 18 '22 at 14:08

How can I resolve PyCallGraphException: The command "dot -Tpng -failed with error code 256 error?

1 Answers1