Error after upgrade to python3.6

“/bin/sh: ./env/bin/pip: No such file or directory
Please install these dependencies using the command:
sudo yum install libtiff-devel libjpeg-devel libzip-devel freetype-devel lcms2-devel libwebp-devel tcl-devel tk-devel
Traceback (most recent call last):
File “/usr/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/lib/python2.7/site-packages/click/core.py”, line 764, in call
return self.main(*args, **kwargs)
File “/usr/lib/python2.7/site-packages/click/core.py”, line 717, in main
rv = self.invoke(ctx)
File “/usr/lib/python2.7/site-packages/click/core.py”, line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/lib/python2.7/site-packages/click/core.py”, line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/lib/python2.7/site-packages/click/core.py”, line 555, 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
"

You may need to run that command as recommended to get the dependencies installed.