pip install failed w/ message "error: invalid command 'egg_info'"

當使用 pip 安裝 package 時若遇到以下錯誤訊息

C:\>pip install django-social-auth3
Downloading/unpacking django-social-auth3
  Running setup.py (path:c:\docume~1\admini~1\locals~1\temp\pip_build_Administrator\django-social-auth3\setup.
py) egg_info for package django-social-auth3
...
...
...
error: invalid command 'egg_info'

----------------------------------------
Cleaning up...
Command python setup.py egg_info failed with error code 1 in c:\docume~1\admini~1\locals~1\temp\pip_build_Admi
nistrator\django-social-auth3
Storing debug log for failure in C:\Documents and Settings\Administrator\pip\pip.log



 這是因為 python package 的發佈從已合併到 setup_tools, 故地址已經改變. 你必需更新 pip 的 update script 到 v0.7版或以後

C:\>pip install --upgrade setuptools
或
C:\>easy_install -U setuptools