Error on bench update develop branch - Egg-link does not match installed location of pdfkit

Hi there,

got an error running bench update on develop branch:

Requirement already up-to-date: pip in ./env/lib/python2.7/site-packages
Exception:
Traceback (most recent call last):
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/commands/install.py", line 342, in run
    prefix=options.prefix_path,
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/req/req_set.py", line 778, in install
    requirement.uninstall(auto_confirm=True)
  File "/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/req/req_install.py", line 703, in uninstall
    '(at %s)' % (link_pointer, self.name, dist.location)
AssertionError: Egg-link  does not match installed location of pdfkit (at /home/frappe/frappe-bench/env/src/pdfkit)
Traceback (most recent call last):
  File "/usr/local/bin/bench", line 11, in <module>
    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 716, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 696, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 1060, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 889, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 534, in invoke
    return callback(*args, **kwargs)
  File "/home/frappe/.bench/bench/commands/update.py", line 62, in update
    _update(pull, patch, build, bench, auto, restart_supervisor, requirements, no_backup, upgrade, force=force, reset=reset)
  File "/home/frappe/.bench/bench/commands/update.py", line 81, in _update
    update_requirements(bench_path=bench_path)
  File "/home/frappe/.bench/bench/utils.py", line 375, in update_requirements
    install_requirements(pip, req_file)
  File "/home/frappe/.bench/bench/utils.py", line 379, in install_requirements
    exec_cmd("{pip} install -q -r {req_file}".format(pip=pip, req_file=req_file))
  File "/home/frappe/.bench/bench/utils.py", line 127, in exec_cmd
    raise CommandFailedError(cmd)
bench.utils.CommandFailedError: ./env/bin/pip install -q -r ./apps/frappe/requirements.txt

It seems the error is due by pdfkit path:

AssertionError: Egg-link does not match installed location of pdfkit (at /home/frappe/frappe-bench/env/src/pdfkit)

Can u please have a look?

Thx