如何通过Homebrew重新安装python@2？解决依赖工具执行报错

Hey there, I’ve dealt with this exact scenario when Python 2.7 was removed from Homebrew’s core repo, so let’s work through this together.

Step 1: Reinstall Python@2 Using brew extract #

Since Python@2 was deleted from Homebrew core, you’ll need to create your own tap (a custom Homebrew formula repository) to host the old Python@2 formula. Here’s how to do it:

1. Create a new custom tap
   Replace <your-username> with your GitHub username (you don’t even need to create the repo on GitHub first—Homebrew handles the local setup):

   brew tap-new <your-username>/python2
   

   For example, if your GitHub username is Pauline, this would be:

   brew tap-new pauline/python2
   

2. Extract the Python@2 formula to your tap
   Run this command to pull the deleted Python@2 formula from Homebrew’s git history into your custom tap:

   brew extract python@2 <your-username>/python2
   

3. Install Python@2 from your custom tap
   Now you can install Python@2 just like any other formula:

   brew install <your-username>/python2/python@2
   

   This will restore the /usr/local/opt/python@2/bin/python2.7 path that your tools are looking for.

Step 2: Fix Dependent Tools (awscli, sshuttle, letsencrypt) #

For awscli #

The SyntaxWarnings you’re seeing are from the jmespath library bundled with awscli v2—they’re harmless but annoying. To fix them:

1. Access awscli’s isolated Python environment and upgrade jmespath:

   /usr/local/Cellar/awscli/2.0.0/libexec/bin/python -m pip install --upgrade jmespath
   

   This will replace the outdated jmespath version with one that fixes the is vs == syntax issue.

   Note: awscli v2 uses Python 3 natively, so once you fix this warning, you shouldn’t need Python@2 for awscli anymore. But if you still have older scripts tied to awscli v1 (which required Python 2), you can install v1 via your custom tap or use a virtual environment.

For sshuttle, letsencrypt, and other Python@2-dependent tools #

Once Python@2 is reinstalled, simply reinstall these tools to re-link them to the correct Python path:

brew reinstall sshuttle letsencrypt

This will update their shebang lines to point to your newly installed /usr/local/opt/python@2/bin/python2.7.

A Quick Note on Python 2 EOL #

While this fixes your immediate issue, keep in mind Python 2 reached end-of-life in 2020. Whenever possible, migrate to Python 3 versions of your tools:

• awscli v2 is fully Python 3 compatible (you’re already using it!)
• sshuttle has Python 3 support in newer versions
• Let’s Encrypt’s Certbot now uses Python 3 by default

Migrating will save you from future compatibility headaches.

内容的提问来源于stack exchange，提问作者Pauline