Unable to clear-cache using bench clear-cache command

Traceback (most recent call last):
File “/usr/lib/python3.6/runpy.py”, line 193, in _run_module_as_main
main”, mod_spec)
File “/usr/lib/python3.6/runpy.py”, line 85, in _run_code
exec(code, run_globals)
File “/home/frappe/frappe-bench/apps/frappe/frappe/utils/bench_helper.py”, lin e 97, in
main()
File “/home/frappe/frappe-bench/apps/frappe/frappe/utils/bench_helper.py”, lin e 18, in main
click.Group(commands=commands)(prog_name=‘bench’)
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 764, in call
return self.main(*args, **kwargs)
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 717, in main
rv = self.invoke(ctx)
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/core.py” , line 555, in invoke
return callback(*args, **kwargs)
File “/home/frappe/frappe-bench/env/lib/python3.6/site-packages/click/decorato rs.py”, line 17, in new_func
return f(get_current_context(), *args, **kwargs)
File “/home/frappe/frappe-bench/apps/frappe/frappe/commands/init.py”, line 25, in _func
ret = f(frappe._dict(ctx.obj), *args, **kwargs)
File “/home/frappe/frappe-bench/apps/frappe/frappe/commands/utils.py”, line 45 , in clear_cache
for site in context.sites:
TypeError: ‘NoneType’ object is not iterable

I was able to fix this issues with