NoMethodError: undefined method `post' for nil:NilClass

[kamaradclimber]

* Operating system:                linux
* Ruby implementation:             Ruby
* `concurrent-ruby` version:       1.1.2
* `concurrent-ruby-ext` installed: no
* `concurrent-ruby-edge` used:     no

When using concurrent-ruby (1.1.2), the following code:

 task = Concurrent::TimerTask.new(run_now: true, execution_interval: 2) do
  sleep 5
end
task.execute

throws:

NoMethodError: undefined method `post' for nil:NilClass
from /home/g_seux/.gem/ruby/2.5.0/gems/concurrent-ruby-1.1.2/lib/concurrent/executor/timer_set.rb:101:in `ns_post_task'

This did not happen with 1.0.5

[delner]

Having this same issue. From what I can see Concurrent.global_io_executor now returns nil, so if the code you were depending on was getting an executor from that so it could call #post against it, it will raise this error.

That Concurrent.global_io_executor changed in implementation between 1.0.5 and 1.1.2: it used to return a ThreadPoolExecutor, it now is meant to return a CachedThreadPool. Problem is, that CachedThreadPool is undefined.

Adding require 'concurrent/executor/cached_thread_pool' to my code fixed this issue for me.

[pitr-ch]

From the fix I deduce that you are requiring just part of the concurrent-ruby not the whole gem. Is that correct? That's not officially supported at the moment (only require 'concurrent' is) so even if we try to make it work sometimes problems get through, see #714. I'll release 1.1.3 with a fix, thanks for investigating.

[pitr-ch]

1.1.3 is out, please reopen if it did not fix the issue.

[delner]

@pitr-ch I can't speak for @kamaradclimber but this is the case on my end; we were only including Future.

Thanks for the quick release! Works for us.

[pitr-ch]

Thanks for confirming. This type of issues should not happen again after #714 is implemented.