raise JSONDecodeError("Expecting value", s, err.value) from None json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

[rambhaskark]

Getting the below error while trying to run the tool.

(.venv) [cfn-template]$ cat aws-waf-security-automations.yml | cfviz | dot -Tsvg -oexample.svg
-bash: dot: command not found
Traceback (most recent call last):
File "/home/rambhaskar/cloud-formation-viz/.venv/bin/cfviz", line 33, in
sys.exit(load_entry_point('cloud-formation-viz==0.0.1', 'console_scripts', 'cfviz')())
File "/home/rambhaskar/cloud-formation-viz/.venv/lib/python3.10/site-packages/cloud_formation_viz-0.0.1-py3.10.egg/cloud_formation_viz/main.py", line 22, in main
template = open_cfn(sys.argv)
File "/home/rambhaskar/cloud-formation-viz/.venv/lib/python3.10/site-packages/cloud_formation_viz-0.0.1-py3.10.egg/cloud_formation_viz/main.py", line 47, in open_cfn
template = json.load(sys.stdin)
File "/usr/local/lib/python3.10/json/init.py", line 293, in load
return loads(fp.read(),
File "/usr/local/lib/python3.10/json/init.py", line 346, in loads
return _default_decoder.decode(s)
File "/usr/local/lib/python3.10/json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/local/lib/python3.10/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)