So You Hosed Your Mac OS Python Install

Mac OS ships with Python 2.7, but before long most users will want to install Python 3. The easiest way to do this is via Homebrew.

Everything is fine and dandy until one day you try to run create a Python 3 virtual environment and get an error message:

dyld: Library not loaded: @executable_path/../.Python
  Referenced from: /Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6
  Reason: image not found
Abort trap: 6

You do some Googling and figure you just need to uninstall and reinstall Python 3:

brew remove python3
brew cleanup && brew prune
brew install python3

Homebrew installs Python3 successfully, so you update pip3 as the installer recommends…

pip3 install --upgrade pip setuptools wheel

…and get the same error you had before:

dyld: Library not loaded: @executable_path/../.Python
  Referenced from: /Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6
  Reason: image not found
Abort trap: 6

At this point, you become concerned. Further Googling turns up some people suggesting you’ll need to take drastic measures; e.g. re-install Mac OS.

Take a deep breath, and try something else. Run

which python3

and figure out where your Python 3 is installed. Assuming it is something like /Library/Frameworks/Python.framework/Versions/3.6/bin/python, delete everything under and including /Library/Frameworks/Python.framework.

Just to be sure, run

brew doctor

and if it reports any broken symlinks, run

brew prune

again.

Finally, reinstall Python3 using Homebrew.

brew install python3

With any luck, Python 3 should be back to normal!