Invalid reference to os.errno in tempfile_services.py prevents ray to start in python 3.7

[bmorier]

System information

• Linux Ubuntu 18.04:
• ray installed from wheel:
• Ray version: 0.6.2
• python 3.7:
• ray start --head --redis-port 7777:

Describe the problem

There is an invalid reference for os.errno in ray/tempfile_services.py that causes ray to not start in python 3.7.

Source code / logs

Using IP address 172.31.3.49 for this node.
Traceback (most recent call last):
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/tempfile_services.py", line 58, in try_to_create_directory
os.makedirs(directory_path)
File "/home/ubuntu/anaconda3/lib/python3.7/os.py", line 221, in makedirs
mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/tmp/ray/session_2019-01-30_00-44-20_3957'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/ubuntu/anaconda3/bin/ray", line 11, in
sys.exit(main())
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/scripts/scripts.py", line 744, in main
return cli()
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/click/core.py", line 764, in call
return self.main(*args, **kwargs)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/click/core.py", line 717, in main
rv = self.invoke(ctx)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/click/core.py", line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/click/core.py", line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/click/core.py", line 555, in invoke
return callback(*args, **kwargs)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/scripts/scripts.py", line 286, in start
node = ray.node.Node(ray_params, head=True, shutdown_at_exit=False)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/node.py", line 86, in init
self.start_ray_processes()
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/node.py", line 274, in start_ray_processes
get_logs_dir_path()))
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/tempfile_services.py", line 106, in get_logs_dir_path
logs_dir = os.path.join(get_temp_root(), "logs")
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/tempfile_services.py", line 94, in get_temp_root
try_to_create_directory(_temp_root)
File "/home/ubuntu/anaconda3/lib/python3.7/site-packages/ray/tempfile_services.py", line 60, in try_to_create_directory
if e.errno != os.errno.EEXIST:
AttributeError: module 'os' has no attribute 'errno'