I recently installed a bunch of dotfiles on my Mac along with some other applications (I changed to iTerm instead of Terminal, and Sublime as my default text editor) but ever since, all my virtual environments have stopped working, although their folders inside .virtualenvs are still there and they give the following error whenever I try to run anything in them:
dyld: Library not loaded: @executable_path/../.Python
Referenced from: /Users/[user]/.virtualenvs/modclass/bin/python
Reason: image not found
Trace/BPT trap: 5
I found the solution to the problem here, so all credit goes to the author.
The gist is that when you create a virtualenv, many symlinks are created to the Homebrew installed Python.
Here is one example:
$ ls -la ~/.virtualenvs/my-virtual-env ... lrwxr-xr-x 1 ryan staff 78 Jun 25 13:21 .Python -> /usr/local/Cellar/python/2.7.7/Frameworks/Python.framework/Versions/2.7/Python ...
When you upgrade Python using Homebrew and then run
brew cleanup, the symlinks in the virtualenv point to paths that no longer exist (because Homebrew deleted them).
The symlinks needs to point to the newly installed Python:
lrwxr-xr-x 1 ryan staff 78 Jun 25 13:21 .Python -> /usr/local/Cellar/python/2.7.8_1/Frameworks/Python.framework/Versions/2.7/Python
The solution is to remove the symlinks in the virtualenv and then recreate them:
find ~/.virtualenvs/my-virtual-env/ -type l -delete virtualenv ~/.virtualenvs/my-virtual-env
It's probably best to check what links will be deleted first before deleting them:
find ~/.virtualenvs/my-virtual-env/ -type l
In my opinion, it's even better to only delete broken symlinks. You can do this using GNU
gfind ~/.virtualenvs/my-virtual-env/ -type l -xtype l -delete
You can install GNU
find with Homebrew if you don't already have it:
brew install findutils
Notice that by default, GNU programs installed with Homebrew tend to be prefixed with the letter
g. This is to avoid shadowing the
find binary that ships with OS X.