["python","pip"]
pip says: THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS FILE. If you have updated the package versions, please update the hashes

I am using pip to install all my python packages but get error as shown in the trace below. What is the problem and how can I solve it? usr@comp:~$ pip install flask Collecting flask Using cached Flask-0.11.1-py2.py3-none-any.whl Collecting itsdangerous>=0.21 (from flask) Using cached itsdangerous-0.24.tar.gz Collecting click>=2.0 (from flask) Using cached click-6.6.tar.gz Collecting Werkzeug>=0.7 (from flask) Using cached Werkzeug-0.11.11-py2.py3-none-any.whl Requirement already satisfied (use --upgrade to upgrade): Jinja2>=2.4 in /usr/lib/python2.7/dist-packages (from flask) Requirement already satisfied (use --upgrade to upgrade): MarkupSafe in /usr/lib/python2.7/dist-packages (from Jinja2>=2.4->flask) THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS FILE. If you have updated the package versions, please update the hashes. Otherwise, examine the package contents carefully; someone may have tampered with them. Werkzeug>=0.7 from https://pypi.python.org/packages/a9/5e/41f791a3f380ec50f2c4c3ef1399d9ffce6b4fe9a7f305222f014cf4fe83/Werkzeug-0.11.11-py2.py3-none-any.whl#md5=c63a21eedce9504d223ed89358c4bdc9 (from flask): Expected md5 c63a21eedce9504d223ed89358c4bdc9 Got 13a168aafcc43354b6c79ef44bb0dc71
There is a similar problem (Why does pip fail with bad md5 hash for package?) from 2013 the solution that I tried that worked for me is this: sudo pip install --no-cache-dir flask given by attolee