Hi Francis,

It looks like you might have hit the issue they describe here:
http://askubuntu.com/questions/509283/python-no-module-named-datetime

Basically datetime was apparently rolled into the python binary in a 2.7 point release. I don't know why this was changed but it makes the python binary in your virtualenv incompatible with your system python install.

According to the thread on askubuntu, you have  two options. 

a) Apparently you can re-initialise the virtualenv by running:

virtualenv . 

in your top Firedrake directory. I'm guessing you should do this with the virtualenv deactivated.

or

b) A fresh Firedrake install should work because it will create a fresh virtualenv based on current Python binary.

Regards,

David

On Mon, 27 Jun 2016 at 15:20 Francis Poulin <fpoulin@uwaterloo.ca> wrote:
Hello,

I recently updated my  ubuntu from 14.04 to 16.04.  I tried running firedrake and it failed. 

I also tried updating firedrake and it failed, see below.

Do I need to install it from scratch or should it be possible to update it with a new OS?

Cheers, Francis



Installing pip dependencies for COFFEE
/home/fpoulin/software/firedrake/bin/pip install -r COFFEE/requirements.txt

Traceback (most recent call last):
  File "/home/fpoulin/software/firedrake/bin/pip", line 7, in <module>
    from pip import main
  File "/home/fpoulin/software/firedrake/local/lib/python2.7/site-packages/pip/__init__.py", line 14, in <module>
    from pip.utils import get_installed_distributions, get_prog
  File "/home/fpoulin/software/firedrake/local/lib/python2.7/site-packages/pip/utils/__init__.py", line 27, in <module>
    from pip._vendor import pkg_resources
  File "/home/fpoulin/software/firedrake/local/lib/python2.7/site-packages/pip/_vendor/pkg_resources/__init__.py", line 36, in <module>
    import plistlib
  File "/usr/lib/python2.7/plistlib.py", line 62, in <module>
    import datetime
ImportError: No module named datetime
Traceback (most recent call last):
  File "../bin/firedrake-update", line 974, in <module>
    pip_requirements(p)
  File "../bin/firedrake-update", line 377, in pip_requirements
    run_pip_install(["-r", "%s/requirements.txt" % package])
  File "../bin/firedrake-update", line 364, in run_pip_install
    check_call(pipinstall + pipargs)
  File "../bin/firedrake-update", line 211, in check_call
    subprocess.check_call(arguments, env=env)
  File "/usr/lib/python2.7/subprocess.py", line 541, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['/home/fpoulin/software/firedrake/bin/pip', 'install', '-r', 'COFFEE/requirements.txt']' returned non-zero exit status 1

------------------
Francis Poulin                    
Associate Professor
Department of Applied Mathematics
University of Waterloo

email:           fpoulin@uwaterloo.ca
Web:            https://uwaterloo.ca/poulin-research-group/
Telephone:  +1 519 888 4567 x32637