Spyder won't launch if mccabe is upgraded to 0.7.0

Issue Report Checklist

• [v] Searched the issues page for similar reports
• [v] Read the relevant sections of the Spyder Troubleshooting Guide and followed its advice
• Reproduced the issue after updating with conda update spyder (or pip, if not using Anaconda)
• Could not reproduce inside jupyter qtconsole (if console-related)
• [v] Tried basic troubleshooting (if a bug/error)
  • [v] Restarted Spyder
  • [v] Reset preferences with spyder --reset
  • [v] Reinstalled the latest version of Anaconda
  • [v] Tried the other applicable steps from the Troubleshooting Guide
• [v] Completed the Problem Description, Steps to Reproduce and Version sections below

Problem Description

I recently upgraded my packages and noticed that Spyder will no longer launch after that. Traceback shows that Spyder expected a mccabe version >=0.6.0 and <0.7.0. So I tried downgrade the said package using pip, and the Spyder then launched with no problem. I don’t know if this is a known problem, but I search and found no issues related so I opened one.

What steps reproduce the problem?

1. Launched the Spyder.
2. It won’t launch.

What is the expected output? What do you see instead?

Paste Traceback/Error Below (if applicable)

Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/pkg_resources/__init__.py", line 573, in _build_master
    ws.require(__requires__)
  File "/usr/lib/python3.10/site-packages/pkg_resources/__init__.py", line 891, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python3.10/site-packages/pkg_resources/__init__.py", line 782, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.ContextualVersionConflict: (mccabe 0.7.0 (/usr/lib/python3.10/site-packages), Requirement.parse('mccabe<0.7.0,>=0.6.0'), {'flake8'})

Versions

• Spyder version: 5.3.0
• Python version: 3.10.2 64-bit
• Qt version: 5.15.2
• PyQt version: 5.15.6
• Operating System name/version: Linux 5.15.28-1-MANJARO

Dependencies

# Mandatory:
atomicwrites >=1.2.0          :  1.4.0 (OK)
chardet >=2.0.0               :  4.0.0 (OK)
cloudpickle >=0.5.0           :  2.0.0 (OK)
cookiecutter >=1.6.0          :  1.7.3 (OK)
diff_match_patch >=20181111   :  20200713 (OK)
intervaltree >=3.0.2          :  3.1.0 (OK)
IPython >=7.31.1;<8.0.0       :  7.32.0 (OK)
jedi >=0.17.2;<0.19.0         :  0.18.1 (OK)
jellyfish >=0.7               :  0.9.0 (OK)
jsonschema >=3.2.0            :  3.2.0 (OK)
keyring >=17.0.0              :  23.4.0 (OK)
nbconvert >=4.0               :  6.4.3 (OK)
numpydoc >=0.6.0              :  1.1.0 (OK)
parso >=0.7.0;<0.9.0          :  0.8.2 (OK)
pexpect >=4.4.0               :  4.8.0 (OK)
pickleshare >=0.4             :  0.7.5 (OK)
psutil >=5.3                  :  5.9.0 (OK)
pygments >=2.0                :  2.11.2 (OK)
pylint >=2.5.0                :  2.12.2 (OK)
pyls_spyder >=0.4.0           :  0.4.0 (OK)
pylsp >=1.4.1;<1.5.0          :  1.4.1 (OK)
pylsp_black >=1.2.0           :  1.2.0 (OK)
qdarkstyle >=3.0.2;<3.1.0     :  3.0.2 (OK)
qstylizer >=0.1.10            :  0.2.1 (OK)
qtawesome >=1.0.2             :  1.0.3 (OK)
qtconsole >=5.3.0;<5.4.0      :  5.3.0 (OK)
qtpy >=2.0.1                  :  2.0.1 (OK)
rtree >=0.9.7                 :  0.9.7 (OK)
setuptools >=49.6.0           :  59.3.0 (OK)
sphinx >=0.6.6                :  4.4.0 (OK)
spyder_kernels >=2.3.0;<2.4.0 :  2.3.0 (OK)
textdistance >=4.2.0          :  4.2.2 (OK)
three_merge >=0.1.1           :  0.1.1 (OK)
watchdog >=0.10.3             :  0.10.7 (OK)
xdg >=0.26                    :  0.27 (OK)
zmq >=17                      :  22.3.0 (OK)

# Optional:
cython >=0.21                 :  0.29.28 (OK)
matplotlib >=3.0.0            :  3.5.1 (OK)
numpy >=1.7                   :  1.22.3 (OK)
pandas >=1.1.1                :  1.4.1 (OK)
scipy >=0.17.0                :  1.8.0 (OK)
sympy >=0.7.3                 :  1.10 (OK)

[ccordoba12]

Look, rolling release distros work well for simple things, but not for something like Spyder, which has more than 100 dependencies between direct and indirect ones. For more thorough discussions about this point, please see:

• https://github.com/spyder-ide/spyder/issues/17155#issuecomment-1013740232
• https://github.com/spyder-ide/spyder/issues/17155#issuecomment-1014105244

[ccordoba12]

Is MUCH simple to use Spyder from Arch Linux

No, it’s not. As I said above, Spyder is always semi-broken on Arch (and other rolling release distros, I guess, but the only one we receive reports for is Arch).

That’s why now we advise our users to stay away from the Arch packages. Furthermore, we’d really prefer if Arch would stop distributing Spyder. That’s because Spyder is never going to work reliably on Arch given that it’s always trying to force Spyder to work with dependencies is not ready for.

I guess the “.0-1” update is nothing,

I don’t know, but sometimes that’s a really bad guess (e.g. Jedi has broken us in x.x.x releases)

why spyder won’t allow me to ignore that?

Because it’s not something we can solve here (as the traceback makes it clear). The problem is in flake8, which requires mccable >=0.6.0,<0.7.0. And we follow the same requirement in python-lsp-server, which depends on both projects (so this is an issue in a dependency of a Spyder dependency, over which we have no control). Without those requirements, either Spyder crashes or python-lsp-server probably does, which breaks our code completion and linting facilities.

ps.: Installing PIP packages is NOT Recommended by Arch Linux maintainers.

I didn’t say you should run sudo pip, which I know is very dangerous. I said you need to use a virtualenv:

Instead, please install Spyder with Anaconda or with pip in a virtualenv.