can not start scylla on python3 virtualenv

[yangsui9999]

Describe the bug
After installed scylla using pip cannot start scylla

To Reproduce
Here's my steps

1. Working with python3 on virtual env.

(autocoin) ➜  ~ python
Python 3.6.5 (default, Apr 25 2018, 14:23:58)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

2. Install scylla

pip install scylla

3. Start scylla in itermal2

scylla

4. Got error
   error logs:

2018-05-28 - 23:30:50 DEBUG: create new connection
2018-05-28 - 23:30:50 INFO: Scheduler starts...
2018-05-28 - 23:30:50 DEBUG: feed 9 providers...
2018-05-28 - 23:30:50 INFO: Start python scheduler
2018-05-28 - 23:30:50 INFO: worker_process started
2018-05-28 - 23:30:50 INFO: validator_thread started
2018-05-28 - 23:30:50 INFO: Start the web server
[2018-05-28 23:30:50 +0800] [27105] [INFO] Goin' Fast @ http://0.0.0.0:8899
2018-05-28 - 23:30:50 DEBUG: fetch_ips...
2018-05-28 - 23:30:50 DEBUG: Get a provider from the provider queue: A2uProvider
[2018-05-28 23:30:50 +0800] [27105] [INFO] Starting worker [27105]
objc[27108]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called.
objc[27108]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.

And I cannot open http://0.0.0.0:8899/

Screenshots

Desktop :

• OS: macOS 10.13.4

[imWildCat]

Thanks for your issue!

I've installed Python 3.6.5 on my Mac and reproduced your problem successfully.

Try to add this environment variable before start scylla:

export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES

If you cannot solve this problem by doing as described above, please let me know.

Since it is said that this is a bug of Python, I tend not to fix it (ansible/ansible#34056 (comment)).

Reference: ansible/ansible#32499 (comment)

[yangsui9999]

@imWildCat after add OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES to my environment variable, can start scylla right.

[imWildCat]

@yangsui9999 Glad to see this. Thank you!