pip2未将软件包更新为最新版本

我正在尝试将PRAW软件包的版本pip2从2.1.3更新到最新版本（2.1.4），但是由于某种原因，在找到版本2.1.4之后，它将继续重新安装2.1.3。

% pip2 search praw             
praw                      - PRAW, an acronym for `Python Reddit API Wrapper`, is a python      package that allows for simple access to reddit's API.
  INSTALLED: 2.1.3
  LATEST:    2.1.4

这是详细的日志。我已经尝试过-U，--update并且sudo pip2 install praw==2.1.4

Downloading/unpacking praw==2.1.4
  Running setup.py egg_info for package praw
    running egg_info
    writing requirements to pip-egg-info/praw.egg-info/requires.txt
    writing pip-egg-info/praw.egg-info/PKG-INFO
    writing top-level names to pip-egg-info/praw.egg-info/top_level.txt
    writing dependency_links to pip-egg-info/praw.egg-info/dependency_links.txt
    writing entry points to pip-egg-info/praw.egg-info/entry_points.txt
    warning: manifest_maker: standard file '-c' not found

    reading manifest file 'pip-egg-info/praw.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    writing manifest file 'pip-egg-info/praw.egg-info/SOURCES.txt'
  Requested praw==2.1.4, but installing version 2.1.3
Requirement already satisfied (use --upgrade to upgrade): requests>=1.2.0 in /usr/lib/python2.7/site-packages (from praw==2.1.4)
Requirement already satisfied (use --upgrade to upgrade): six in /usr/lib/python2.7/site-packages (from praw==2.1.4)
Requirement already satisfied (use --upgrade to upgrade): update-checker>=0.5 in /usr/lib/python2.7/site-packages (from praw==2.1.4)
Requirement already satisfied (use --upgrade to upgrade): setuptools in /usr/lib/python2.7/site-packages (from update-checker>=0.5->praw==2.1.4)
Installing collected packages: praw
  Found existing installation: praw 2.1.3
    Uninstalling praw:
      Removing file or directory /usr/bin/praw-multiprocess
      Removing file or directory /usr/lib/python2.7/site-packages/praw-2.1.3-py2.7.egg-info
      Removing file or directory /usr/lib/python2.7/site-packages/praw/__init__.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/__init__.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/decorators.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/decorators.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/errors.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/errors.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/handlers.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/handlers.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/helpers.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/helpers.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/internal.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/internal.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/multiprocess.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/multiprocess.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/objects.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/objects.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/praw.ini
      Removing file or directory /usr/lib/python2.7/site-packages/praw/settings.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/settings.pyc
      Removing file or directory /usr/lib/python2.7/site-packages/praw/tests/__init__.py
      Removing file or directory /usr/lib/python2.7/site-packages/praw/tests/__init__.pyc
      Successfully uninstalled praw
  Running setup.py install for praw
    running install
    running build
    running build_py
    running install_lib
    creating /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/praw.ini -> /usr/lib/python2.7/site-packages/praw
    creating /usr/lib/python2.7/site-packages/praw/tests
    copying build/lib/praw/tests/__init__.py -> /usr/lib/python2.7/site-packages/praw/tests
    copying build/lib/praw/internal.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/__init__.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/objects.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/handlers.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/decorators.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/settings.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/errors.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/multiprocess.py -> /usr/lib/python2.7/site-packages/praw
    copying build/lib/praw/helpers.py -> /usr/lib/python2.7/site-packages/praw
    byte-compiling /usr/lib/python2.7/site-packages/praw/tests/__init__.py to __init__.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/internal.py to internal.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/__init__.py to __init__.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/objects.py to objects.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/handlers.py to handlers.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/decorators.py to decorators.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/settings.py to settings.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/errors.py to errors.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/multiprocess.py to multiprocess.pyc
    byte-compiling /usr/lib/python2.7/site-packages/praw/helpers.py to helpers.pyc
    running install_egg_info
    running egg_info
    writing requirements to praw.egg-info/requires.txt
    writing praw.egg-info/PKG-INFO
    writing top-level names to praw.egg-info/top_level.txt
    writing dependency_links to praw.egg-info/dependency_links.txt
    writing entry points to praw.egg-info/entry_points.txt
    warning: manifest_maker: standard file '-c' not found

    reading manifest file 'praw.egg-info/SOURCES.txt'
    reading manifest template 'MANIFEST.in'
    writing manifest file 'praw.egg-info/SOURCES.txt'
    Copying praw.egg-info to /usr/lib/python2.7/site-packages/praw-2.1.3-py2.7.egg-info
    running install_scripts
    Installing praw-multiprocess script to /usr/bin
    writing list of installed files to '/tmp/pip-NKy2i9-record/install-record.txt'
Successfully installed praw
Cleaning up...

这是在运行Python 2.7.5的Arch Linux上。