Fixing an assertion error on pip list

Thursday, Mar 5, 2015 15:35 · 154 words · 1 minute read python

The Problem

Getting the following assertion error when trying to list the Python packages:

pip list

Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/pip/", line 134, in main
    status =, args)
File "/usr/lib/python2.7/dist-packages/pip/commands/", line 80, in run
File "/usr/lib/python2.7/dist-packages/pip/commands/", line 127, in run_listing
File "/usr/lib/python2.7/dist-packages/pip/commands/", line 136, in output_package_listing
    if dist_is_editable(dist):
File "/usr/lib/python2.7/dist-packages/pip/", line 347, in dist_is_editable
    req = FrozenRequirement.from_dist(dist, [])
File "/usr/lib/python2.7/dist-packages/pip/", line 194, in from_dist
    assert len(specs) == 1 and specs[0][0] == '=='

means that either pip is outdated on the host machine or the distribute package.

The Solution

Upgrading pip

pip can be upgraded using the following set of commands:

# download via curl
curl -O
# download via wget

# installing pip
sudo python


pip install -U pip

More information about pip installation and upgrade can be found here.

Upgrading the distribute package

pip install --upgrade distribute
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