What does "error: option --single-version-externally-managed not recognized" indicate?

Question

I seem to have suddenly started to encounter the error error: option --single-version-externally-managed not recognized when using pip install with various packages (including PyObjC and astropy).

I've never seen this error before, but it's now also showing up on travis-ci builds for which nothing has changed.

Does this error indicate an out of date distribution?

Some incorrectly specified option in setup.py?

Something else entirely?

Answer 1

Add --egg option

pip install --egg SCons

I use pip version 1.4.1

Answer 2

New Update:

Install the latest version of setuptools. If you still get the error, install wheel as well.

pip install -U setuptools
pip install -U wheel

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Original Answer / More Details:

--single-version-externally-managed is an option used for Python packages instructing the setuptools module to create a Python package which can be easily managed by the host's package manager if needed, like Yum or Apt.

If you're seeing this message, you may have an old version of setuptools or Python. Try using Distribute, which is a newer version of setuptools and is backwards compatible. These packages may expect that you have it already.

https://pypi.python.org/pypi/distribute

Edit: At this point, distribute has been merged into the main setuptools project. Just install the latest version of setuptools. As @wynemo indicated, you may wish to use the --egg option instead, as it's more appropriate for those doing manual installations where you're not intending to create a system package for distribution.

Answer 3

Installing wheel resolved this issue with recent pip (I used 8.1.2):

pip install wheel

Answer 4

Try upgrading setuptools like this:

pip install --upgrade setuptools

Answer 5

I was having this problem. It turned out it was a problem with the file permissions on my pip cache.

If you see a message at the very beginning of your pip output like

The directory '/home/ubuntu/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/home/ubuntu/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.

you might have the same problem. You can resolve it by either ensuring that you have proper file permissions on your pip cache (something like chown -R $(whoami) /home/ubuntu/.cache/pip) or, if you're on a UNIX, you can set the pip cache location with the XDG_CACHE_HOME env var to some folder you do own.