M1 Mac Ventura下Homebrew安装Python@3后post-install步骤失败求助

环境信息 #

• M1 Mac，系统版本Ventura 13.0
• Homebrew版本4.0.6

问题描述 #

执行brew install python@3安装Python后，post-install步骤失败；重试brew postinstall python@3.11问题依旧。

关键错误日志 #

==> //opt/homebrew/Cellar/python@3.11/3.11.2_1/bin/python3.11 -m ensurepip
==> //opt/homebrew/Cellar/python@3.11/3.11.2_1/bin/python3.11 -m pip install -v --no-deps --no-index --upgrade --isolated --target=//opt/homebrew/lib/python3.11/site-
最后15行日志来自 /Users/zhangfan/Library/Logs/Homebrew/python@3.11/post_install.02.python3.11:
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pip/_internal/cli/req_command.py", line 411, in get_requirements
    req_to_add = install_req_from_line(
                 ^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pip/_internal/req/constructors.py", line 395, in install_req_from_line
    return InstallRequirement(
           ^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pip/_internal/req/req_install.py", line 127, in __init__
    self.local_file_path = self.link.file_path
                           ^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pip/_internal/models/link.py", line 330, in file_path
    return url_to_path(self.url)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/python@3.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pip/_internal/utils/urls.py", line 43, in url_to_path
    raise ValueError(
ValueError: 该平台不支持非本地文件URI: 'file://opt/homebrew/Cellar/python%403.11/3.11.2_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/ensurepip/_bundled/setuptools-65.6.3-py3-none-any.whl'
警告: Post-install步骤未成功完成
你可以尝试再次执行:
  brew postinstall python@3.11

错误原因 #

错误核心是pip无法处理非本地文件URI，问题出在文件路径格式：file://opt/...缺少根路径的斜杠，正确格式应为file:///opt/...（三个斜杠）。这是Homebrew生成pip安装命令时的路径格式错误导致的。

解决步骤 #

• 卸载当前Python@3.11

  brew uninstall python@3.11
  

• 清理残留文件

  rm -rf /opt/homebrew/Cellar/python@3.11
  rm -rf /Users/zhangfan/Library/Logs/Homebrew/python@3.11
  

• 重新安装Python@3.11

  brew install python@3.11
  

• 手动补全post-install（若仍失败）
  直接调用ensurepip完成pip和setuptools的安装：

  /opt/homebrew/Cellar/python@3.11/3.11.2_1/bin/python3.11 -m ensurepip --upgrade --default-pip
  

内容的提问来源于stack exchange，提问作者vince zhang