Windows子系统Ubuntu重装Python3遇init_fs_encoding致命错误求助

问题背景 #

为排查Windows上Ubuntu子系统（WSL）的问题，卸载所有Python实例后原问题解决，但执行sudo apt install python3时无法完成重装，核心报错为找不到encodings模块。

完整安装报错日志 #

$ sudo apt install python3
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  libpython3-stdlib python3-minimal python3.10
Suggested packages:
  python3-doc python3-tk python3-venv python3.10-venv python3.10-doc
The following NEW packages will be installed:
  libpython3-stdlib python3 python3-minimal python3.10
0 upgraded, 4 newly installed, 0 to remove and 35 not upgraded.
1 not fully installed or removed.
Need to get 0 B/562 kB of archives.
After this operation, 905 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up python3.10-minimal (3.10.12-1~22.04.6) ...
# Empty sitecustomize.py to avoid a dangling symlink
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Python path configuration:
  PYTHONHOME = (not set)
  PYTHONPATH = (not set)
  program name = '/usr/bin/python3.10'
  isolated = 0
  environment = 0
  user site = 1
  import site = 0
  sys._base_executable = '/usr/bin/python3.10'
  sys.base_prefix = '/usr'
  sys.base_exec_prefix = '/usr'
  sys.platlibdir = 'lib'
  sys.executable = '/usr/bin/python3.10'
  sys.prefix = '/usr'
  sys.exec_prefix = '/usr'
  sys.path = [
    '/usr/lib/python310.zip',
    '/usr/lib/python3.10',
    '/usr/lib/lib-dynload',
  ]
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
ModuleNotFoundError: No module named 'encodings'

Current thread 0x00007fcf47778000 (most recent call first):
  <no Python frame>
dpkg: error processing package python3.10-minimal (--configure):
 installed python3.10-minimal package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 python3.10-minimal
E: Sub-process /usr/bin/dpkg returned an error code (1)

核心错误 #

Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
ModuleNotFoundError: No module named 'encodings'

解决思路 #

• 清理损坏包与缓存
  强制移除损坏的python3.10-minimal包：

  sudo dpkg --remove --force-remove-reinstreq python3.10-minimal
  

  清理APT缓存并移除无用依赖：

  sudo apt clean && sudo apt autoremove
  

• 修复APT依赖链
  配置未完成的包：

  sudo dpkg --configure -a
  

  修复损坏的依赖：

  sudo apt --fix-broken install
  

• 重新安装Python核心组件
  先重装python3.10-minimal：

  sudo apt install --reinstall python3.10-minimal
  

  再安装python3：

  sudo apt install python3
  

• 修复文件系统权限（WSL专属检查）
  修复Python安装目录的权限：

  sudo chown -R root:root /usr/lib/python3.10
  

  检查/usr/lib/python310.zip是否存在，若缺失可重新下载对应版本包解压补充。

• 极端方案：重置WSL实例（数据会丢失）
  在Windows命令提示符执行：

  wsl --unregister Ubuntu
  

  之后从应用商店重新安装Ubuntu子系统，再配置环境。

内容的提问来源于stack exchange，提问作者Jim Fell