Python completion not working after update

[sansna]

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Issue Details

Provide a clear description of the problem, including the following key
questions:

1. built ycm months ago with option --all + python3.7
2. works perfectly with python/go/... completers
3. today I did a git pull origin master
4. and rebuilt ycm with python3 ./install.py --all (python version 3.8)
5. go completer works, but python completer failed. (ValueError: No semantic completer exists for filetypes: ['python'])

so, what is the recommended way of building ycm after pulling from master?

• What did you expect to happen?

python completer works

• What actually happened?

It does not find a python completer.
prompts: ycm-core/YouCompleteMe/third_party/ycmd/ycmd/server_state.py", line 91, in GetFiletypeCompleter
raise ValueError(
ValueError: No semantic completer exists for filetypes: ['python']

Contents of YCM, ycmd and completion engine logfiles

Reproduce the issue with vim -Nu /path/to/YCM/vimrc_ycm_minimal, which
enabled debug logging and other useful diagnostics. Include a link to a
gist containing all of the log files listed by :YcmToggleLogs.

OS version, distribution, etc.

MacOS 10.15

Output of build/install commands

No error reported.

[puremourning]

This is a "known" issue that affects some people when switching python versions. It seems to be a problem with Jedi. We're not sure why this happens, but we don't think there's anything that we can do about it. It's something to do with .pyc files.

The solution is to delete the python cached files in Jedi.

• cd /path/to/YCM/third_party/ycmd
• find . -type f -name '*.pyc' -delete

Then just restart vim.

[puremourning]

I updated the nuclear instructions. but thanks for the info. going to lock this so that the solution doesn't get swallowed.