optparse.py がエラーを吐く

症状

python3 が絡むほとんどの処理で optparse.py がエラーを吐いて困った。

e.g.: apt, command-not-found, pip3

エラー内容

$ hoge
Traceback (most recent call last):
  File "/usr/lib/command-not-found", line 25, in <module>
    from optparse import OptionParser
  File "/usr/lib/python3.8/optparse.py", line 1
    nt to [a-zA-Z0-9_]
       ^
SyntaxError: invalid syntax

調査

/usr/lib/command-not-found は python3 で書かれている。

$ file /usr/lib/command-not-found
/usr/lib/command-not-found: Python script, ASCII text executable

/usr/lib/python3.8/optparse.py が壊れているようだ。
このファイルは python3 の基本的なライブラリ。

$ cat /usr/lib/python3.8/optparse.py
nt to [a-zA-Z0-9_]
             in bytes patterns or string patterns with the ASCII flag.
             In string patterns without the ASCII flag, it will match the
             range of Unicode alphanumeric characters (letters plus digits
             plus underscore).
             With LOCALE, it will match the set [0-9_] plus characters defined
             as letters for the current locale.
    \W       Matches the complement of \w.
    \\       Matches a literal backslash.

This module exports the following functions:
    match     Match a regular expression pattern to the beginning of a string.
    fullmatch Match a regular expression pattern to all of a string.
    search    Search a string for the presence of a pattern.
    sub       Substitute occurrences of a pattern found in a string.
    subn      Same as sub, but also return the number of substitutions made.
    split     Split a string by the occurrences of a pattern.
    findall   Find all occurrences of a pattern in a string.
    finditer  Return an iterator yielding a Match object for each match.
    compile   Compile a pattern into a Pattern object.
    purge     Clear the regular expression cache.
    escape    Backslash all non-alphanumerics in a string.

Each function other than purge and escape can take an optional 'flags' argument
consisting of one or more of the following module constants, joined by "|".
A, L, and U are mutually exclusive.
    A  ASCII       For string patterns, make \w, \W, \b, \B, \d, \D
                   match the corresponding ASCII character categories
                   (rath

解決方法

GitHub (https://github.com/python/cpython/tags) の対応するのバージョンの optparse.py で差し替える。

$ python3 -V
Python 3.8.10

-> 今回は 3.8.10 (https://github.com/python/cpython/releases/tag/v3.8.10)

$ wget https://github.com/python/cpython/archive/refs/tags/v3.8.10.tar.gz
$ tar xf v3.8.10.tar.gz
$ sudo cp cpython-3.8.10/Lib/optparse.py /usr/lib/python3.8/optparse.py

解決

$ hoge

Command 'hoge' not found, did you mean:

  command 'hose' from deb netpipes (4.2-8build1)

Try: sudo apt install <deb name>