Crash when running flake8 withouth a path or on root of project

[hmvp]

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Please search on the issue tracker before creating one.

Expected Behavior

Run flake8

Current Behavior

flake8 crashes
This does not show when uninstalling nitpick from env
Running nitpick through pre-commit does work:
pre-commit run nitpick --files setup.py

Steps to Reproduce

$ flake8 .
multiprocessing.pool.RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/local-venv/lib/python3.7/multiprocessing/pool.py", line 121, in worker
    result = (True, func(*args, **kwds))
  File "/local-venv/lib/python3.7/multiprocessing/pool.py", line 44, in mapstar
    return list(map(*args))
  File "/local-venv/lib/python3.7/site-packages/flake8/checker.py", line 676, in _run_checks
    return checker.run_checks()
  File "/local-venv/lib/python3.7/site-packages/flake8/checker.py", line 589, in run_checks
    self.run_ast_checks()
  File "/local-venv/lib/python3.7/site-packages/flake8/checker.py", line 494, in run_ast_checks
    for (line_number, offset, text, _) in runner:
  File "/local-venv/lib/python3.7/site-packages/nitpick/flake8.py", line 51, in run
    yield from itertools.chain(app.config.merge_styles(), self.check_files(True), self.check_files(False))
  File "/local-venv/lib/python3.7/site-packages/nitpick/config.py", line 66, in merge_styles
    style.find_initial_styles(configured_styles)
  File "/local-venv/lib/python3.7/site-packages/nitpick/style.py", line 66, in find_initial_styles
    self.include_multiple_styles(chosen_styles)
  File "/local-venv/lib/python3.7/site-packages/nitpick/style.py", line 113, in include_multiple_styles
    self.include_multiple_styles(sub_styles)
  File "/local-venv/lib/python3.7/site-packages/nitpick/style.py", line 113, in include_multiple_styles
    self.include_multiple_styles(sub_styles)
  File "/local-venv/lib/python3.7/site-packages/nitpick/style.py", line 113, in include_multiple_styles
    self.include_multiple_styles(sub_styles)
  File "/local-venv/lib/python3.7/site-packages/nitpick/style.py", line 98, in include_multiple_styles
    toml_dict = toml.as_data
  File "/local-venv/lib/python3.7/site-packages/nitpick/formats.py", line 128, in as_data
    self.load()
  File "/local-venv/lib/python3.7/site-packages/nitpick/formats.py", line 229, in load
    self._reformatted = toml.dumps(self._data)
  File "/local-venv/lib/python3.7/site-packages/toml/encoder.py", line 67, in dumps
    raise ValueError("Circular reference detected")
ValueError: Circular reference detected
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/local-venv/bin/flake8", line 8, in <module>
    sys.exit(main())
  File "/local-venv/lib/python3.7/site-packages/flake8/main/cli.py", line 22, in main
    app.run(argv)
  File "/local-venv/lib/python3.7/site-packages/flake8/main/application.py", line 363, in run
    self._run(argv)
  File "/local-venv/lib/python3.7/site-packages/flake8/main/application.py", line 351, in _run
    self.run_checks()
  File "/local-venv/lib/python3.7/site-packages/flake8/main/application.py", line 264, in run_checks
    self.file_checker_manager.run()
  File "/local-venv/lib/python3.7/site-packages/flake8/checker.py", line 321, in run
    self.run_parallel()
  File "/local-venv/lib/python3.7/site-packages/flake8/checker.py", line 287, in run_parallel
    for ret in pool_map:
  File "/local-venv/lib/python3.7/multiprocessing/pool.py", line 354, in <genexpr>
    return (item for chunk in result for item in chunk)
  File "/local-venv/lib/python3.7/multiprocessing/pool.py", line 748, in next
    raise value
ValueError: Circular reference detected

Context

Your Environment

• nitpick version used: latest

• Python version: 3.7 and 3.8

• Operating System and version: Ubuntu

• Link to your project:

• Run the following commands and paste the output:

  which python3
  python3 -V
  pip freeze
  cat $(which flake8)

$     which python3
/local-venv/bin/python3
$     python3 -V
Python 3.7.7
$     pip freeze
aiocache==0.11.1
aiofiles==0.5.0
aioredis==1.3.1
alabaster==0.7.12
aniso8601==7.0.0
apache-license-check==1.0.0
apipkg==1.5
appdirs==1.4.4
APScheduler==3.6.0
async-exit-stack==1.0.1
async-generator==1.10
async-timeout==3.0.1
attrs==19.3.0
Authlib==0.14.3
Babel==2.7.0
bandit==1.6.2
black==20.8b1
blinker==1.4
blockdiag==2.0.1
certifi==2020.6.20
cffi==1.14.0
cfgv==3.1.0
chardet==3.0.4
click==7.1.2
colorama==0.4.4
commonmark==0.9.1
contextlib2==0.6.0.post1
coverage==5.1
cryptography==2.9.2
dictdiffer==0.8.1
distlib==0.3.0
dnspython==1.16.0
docutils==0.16
email-validator==1.1.1
execnet==1.7.1
fastapi==0.61.2
fastapi-mail==0.2.5
filelock==3.0.12
flake8==3.8.4
flake8-bandit==2.1.2
flake8-bugbear==20.1.4
flake8-comprehensions==3.3.0
flake8-docstrings==1.5.0
flake8-junit-report==2.1.0
flake8-logging-format==0.6.0
flake8-pep3101==1.3.0
flake8-polyfill==1.0.2
flake8-print==3.1.4
flake8-rst==0.7.2
flake8-rst-docstrings==0.0.14
flake8-tidy-imports==4.1.0
Flask==1.1.2
Flask-DebugToolbar==0.11.0
Flask-Testing==0.8.0
freezegun==1.0.0
funcparserlib==0.3.6
future==0.18.2
gitchangelog==3.0.4
gitdb==4.0.5
GitPython==3.1.3
graphene==2.1.8
graphql-core==2.3.2
graphql-relay==2.0.1
gunicorn==20.0.4
h11==0.9.0
h2==3.2.0
hiredis==1.1.0
hpack==3.0.0
hstspreload==2020.6.16
httptools==0.1.1
httpx==0.12.0
hyperframe==5.2.0
identify==1.4.20
idna==2.9
imagesize==1.2.0
importlib-metadata==1.6.1
influxdb==5.3.0
iniconfig==1.1.1
isort==5.6.4
itsdangerous==1.1.0
jaeger-client==4.3.0
Jinja2==2.11.2
jmespath==0.10.0
MarkupSafe==1.1.1
marshmallow==3.9.1
marshmallow-polyfield==5.9
mccabe==0.6.1
more-itertools==8.6.0
msgpack==0.6.1
mypy==0.790
mypy-extensions==0.4.3
nodeenv==1.4.0
opentracing==2.3.0
opentracing-instrumentation==3.2.1
orjson==3.4.2
packaging==20.4
pathspec==0.8.0
pathtools==0.1.2
pbr==5.4.5
Pillow==7.1.2
pluggy==0.13.1
pre-commit==2.8.2
promise==2.3
py==1.8.2
pycodestyle==2.6.0
pycparser==2.20
pydantic==1.7.1
pydocstyle==3.0.0
pyflakes==2.2.0
Pygments==2.6.1
pyparsing==2.4.7
pystache==0.5.4
pytest==6.1.2
pytest-asyncio==0.14.0
pytest-cov==2.10.1
pytest-forked==1.1.3
pytest-httpx==0.2.0
pytest-xdist==2.1.0
python-dateutil==2.8.1
python-dotenv==0.15.0
python-multipart==0.0.5
python-slugify==4.0.1
pytz==2020.1
PyYAML==5.3.1
recommonmark==0.6.0
redis==3.5.3
regex==2020.6.8
requests==2.24.0
restructuredtext-lint==1.3.1
rfc3986==1.4.0
ruamel.yaml==0.16.12
ruamel.yaml.clib==0.2.2
Rx==1.6.1
schedule==0.5.0
sentry-sdk==0.19.3
seqdiag==2.0.0
six==1.15.0
smmap==3.0.4
sniffio==1.1.0
snowballstemmer==2.0.0
sortedcontainers==2.3.0
Sphinx==3.3.1
sphinx-rtd-theme==0.5.0
sphinxcontrib-applehelp==1.0.2
sphinxcontrib-blockdiag==2.0.0
sphinxcontrib-devhelp==1.0.2
sphinxcontrib-htmlhelp==1.0.3
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==1.0.3
sphinxcontrib-seqdiag==2.0.0
sphinxcontrib-serializinghtml==1.1.4
starlette==0.13.6
Starlette-OpenTracing==0.1.0
stevedore==2.0.0
structlog==20.1.0
termcolor==1.1.0
text-unidecode==1.3
threadloop==1.0.2
thrift==0.13.0
toml==0.10.1
tornado==5.1.1
typed-ast==1.4.1
typing-extensions==3.7.4.3
tzlocal==2.1
ujson==3.0.0
urllib3==1.25.9
uvicorn==0.12.2
uvloop==0.14.0
virtualenv==20.0.24
watchdog==0.10.3
watchgod==0.6
wcwidth==0.2.4
webcolors==1.11.1
websockets==8.1
Werkzeug==1.0.1
wrapt==1.12.1
zipp==3.1.0
$     cat $(which flake8)
#!/local-venv/bin/python3
# -*- coding: utf-8 -*-
import re
import sys
from flake8.main.cli import main
if __name__ == '__main__':
    sys.argv[0] = re.sub(r'(-script\.pyw|\.exe)?$', '', sys.argv[0])
    sys.exit(main())

[hmvp]

BTW: I fully support changing nitpick to a standalone command instead of a flake plugin. Or at least make both possible

[andreoliwa]

I don't know how to reproduce your problem.

• nitpick version used: latest

Nitpick doesn't seem to be installed.
I can't see nitpick==<version> on your pip freeze output above.

File "/local-venv/lib/python3.7/site-packages/toml/encoder.py", line 67, in dumps
raise ValueError("Circular reference detected")
ValueError: Circular reference detected

This looks like a problem the toml package had some time ago: uiri/toml#295
This is already fixed in the latest toml version, which Nitpick is already using: https://github.com/andreoliwa/nitpick/releases/tag/v0.23.1

BTW: I fully support changing nitpick to a standalone command instead of a flake plugin. Or at least make both possible

This is planned for the future. 🙂
See #166 and https://github.com/andreoliwa/nitpick/projects/1#card-41040429