I’ve tried to upgrading my server ubuntu 14.04 to 16.04… after a successful upgrade when i start to update my bench this error below hits…
frappe@server:~/frappe-bench$ bench update
INFO:bench.utils:updating bench
INFO:bench.utils:git pull
Already up-to-date.
INFO:bench.utils:./env/bin/pip install Pillow
Traceback (most recent call last):
File “./env/bin/pip”, line 7, in
from pip import main
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/init.py”, line 21, in
from pip._vendor.requests.packages.urllib3.exceptions import DependencyWarning
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/_vendor/requests/init.py”, line 62, in
from .packages.urllib3.exceptions import DependencyWarning
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/init.py”, line 29, in
import urllib3
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/urllib3/init.py”, line 8, in
from .connectionpool import (
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/urllib3/connectionpool.py”, line 29, in
from .connection import (
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/urllib3/connection.py”, line 2, in
import datetime
ImportError: No module named datetime
Please install these dependencies using the command:
sudo apt-get install -y libtiff5-dev libjpeg8-dev zlib1g-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk
Traceback (most recent call last):
File “/usr/local/bin/bench”, line 11, in
load_entry_point(‘bench’, ‘console_scripts’, ‘bench’)()
File “/home/frappe/.bench/bench/cli.py”, line 40, in cli
bench_command()
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 722, in call
return self.main(*args, **kwargs)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 697, in main
rv = self.invoke(ctx)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 535, in invoke
return callback(*args, **kwargs)
File “/home/frappe/.bench/bench/commands/update.py”, line 60, in update
_update(pull, patch, build, bench, auto, restart_supervisor, restart_systemd, requirements, no_backup, force=force, reset=reset)
File “/home/frappe/.bench/bench/commands/update.py”, line 70, in _update
before_update(bench_path=bench_path, requirements=requirements)
File “/home/frappe/.bench/bench/utils.py”, line 759, in before_update
validate_pillow_dependencies(bench_path, requirements)
File “/home/frappe/.bench/bench/utils.py”, line 767, in validate_pillow_dependencies
exec_cmd(“{pip} install Pillow”.format(pip=pip))
File “/home/frappe/.bench/bench/utils.py”, line 159, in exec_cmd
raise CommandFailedError(cmd)
bench.utils.CommandFailedError: ./env/bin/pip install Pillow
i also tried to install the code below but nothing changes it hits same error… maybe i missed something… please help me, 
sudo apt-get install -y libtiff5-dev libjpeg8-dev zlib1g-dev libfreetype6-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk