Fix virtualenv symlinks after upgrading python with Homebrew and running brew cleanup

fix-venv.sh

#!/usr/bin/env bash
#
# Fix virtualenv symlinks after upgrading python with Homebrew and then running
# `cleanup`.
#
# After upgrading Python using Homebrew and then running `brew cleanup` one can
# get this message while trying to run python:
# dyld: Library not loaded: @executable_path/../.Python
#   Referenced from: /Users/pablo/.venv/my-app/bin/python
#   Reason: image not found
# Trace/BPT trap: 5
#
# This happens because the symlinks in the virtualenv point to paths that no
# longer exist. This script is intended to fix that.

if [[ "$1" == "" ]]; then
  echo "usage:"
  echo -e "\t./$(basename "$0") <VIRUTALENV-DIR>"
  echo "example:"
  echo -e "\t./$(basename "$0") \$HOME/.virtualenvs"
  exit 0
fi

VENVS_DIR="$1"

# check if GNU find is installed
if [[ ! "$(type -P gfind)" ]]; then
  brew install findutils
fi

for entry in $(ls $VENVS_DIR | xargs -n 1 basename); do
  venv_name=$(basename "$entry")
  if [[ -d $VENVS_DIR/$venv_name ]]; then
    # check if Library symlink is broken
    if [ -f $VENVS_DIR/$venv_name/.Python ] && [ "$(gfind $VENVS_DIR/$venv_name/.Python -type l -xtype l)" == "" ]; then
      echo "== Virtualenv [$venv_name] is ok. Path: $VENVS_DIR/$venv_name"
    else
      echo "== Virtualenv [$venv_name] has broken symlinks. Path: $VENVS_DIR/$venv_name"
      echo -e "\tFixing [$venv_name]"
      echo -e "\tRemoving old symlinks..."
      echo -e "\tgfind $VENVS_DIR/$venv_name -type l -xtype l -delete"
      gfind $VENVS_DIR/$venv_name -type l -xtype l -delete
      python_symlink=$(readlink $VENVS_DIR/$venv_name/bin/python)
      python_version=$(echo $python_symlink | sed 's/python//g')
      echo -e "\tUpdating [$venv_name]..."
      if [[ $python_version == 3.* ]]; then
        echo -e "\tvirtualenv --python=$(which python3) $VENVS_DIR/$venv_name"
        /usr/local/bin/virtualenv --python=$(which python3) $VENVS_DIR/$venv_name
      else
        echo -e "\tvirtualenv $VENVS_DIR/$venv_name"
        /usr/local/bin/virtualenv $VENVS_DIR/$venv_name
      fi
    fi
  fi
done

Think you, I ran your script, and output:
==> Downloading https://homebrew.bintray.com/bottles/findutils-4.7.0.big_sur.bottle.tar.gz ==> Downloading from https://d29vzk4ow07wi7.cloudfront.net/fae48a197e0a386fd330d8c48b375b5bb289f5d7105f0d007d94c53f7edc060f?response-content-disposition=attachment%3Bfilename%3D%22findutils-4.7.0.big_sur.bo ######################################################################## 100.0% ==> Pouring findutils-4.7.0.big_sur.bottle.tar.gz ==> Caveats All commands have been installed with the prefix "g". If you need to use these commands with their normal names, you can add a "gnubin" directory to your PATH from your bashrc like: PATH="/usr/local/opt/findutils/libexec/gnubin:$PATH" ==> Summary 🍺 /usr/local/Cellar/findutils/4.7.0: 32 files, 1.8MB == Virtualenv [Django] has broken symlinks. Path: /Users/ezreal/.virtualenvs/Django Fixing [Django] Removing old symlinks... gfind /Users/ezreal/.virtualenvs/Django -type l -xtype l -delete Updating [Django]... virtualenv /Users/ezreal/.virtualenvs/Django created virtual environment CPython3.9.0.final.0-64 in 789ms creator CPython3Posix(dest=/Users/ezreal/.virtualenvs/Django, clear=False, no_vcs_ignore=False, global=False) seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=/Users/ezreal/Library/Application Support/virtualenv) added seed packages: pip==20.2.4, setuptools==50.3.2, wheel==0.35.1 activators BashActivator,CShellActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator == Virtualenv [qianfeng] has broken symlinks. Path: /Users/ezreal/.virtualenvs/qianfeng Fixing [qianfeng] Removing old symlinks... gfind /Users/ezreal/.virtualenvs/qianfeng -type l -xtype l -delete Updating [qianfeng]... virtualenv /Users/ezreal/.virtualenvs/qianfeng created virtual environment CPython3.9.0.final.0-64 in 356ms creator CPython3Posix(dest=/Users/ezreal/.virtualenvs/qianfeng, clear=False, no_vcs_ignore=False, global=False) seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=/Users/ezreal/Library/Application Support/virtualenv) added seed packages: pip==20.2.4, setuptools==50.3.2, wheel==0.35.1 activators BashActivator,CShellActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator
and ran other script:
sudo pip3 install virtualenv virtualenvwrapper
and it is ok;
But now it still throws an exception:
/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python: No module named virtualenvwrapper virtualenvwrapper.sh: There was a problem running the initialization hooks. If Python could not import the module virtualenvwrapper.hook_loader, check that virtualenvwrapper has been installed for VIRTUALENVWRAPPER_PYTHON=/usr/bin/python and that PATH is set properly.
my python version is 3.9 and mac python is 2.7

@EzrealR, I don't really use virtualenvwrapper, but I would recommend you to install virtualenv and virtualenvwrapper without sudo and set the VIRTUALENVWRAPPER_PYTHON to your default Python:

$ deactivate
$ export VIRTUALENVWRAPPER_PYTHON=$(which python)

@pv8
Thank you for your reply.

i ran all scripts and is also wrong:
sudo pip3 uninstall virtualenv virtualenvwrapper
pip instll virtualenv virtualenvwrapper
export VIRTUALENVWRAPPER_PYTHON=$(which python)
But now it still throws an exception:
``/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python: No module named virtualenvwrapper
virtualenvwrapper.sh: There was a problem running the initialization hooks.

If Python could not import the module virtualenvwrapper.hook_loader,
check that virtualenvwrapper has been installed for
VIRTUALENVWRAPPER_PYTHON=/usr/bin/python and that PATH is
set properly.``