exceptions in threads

[hackhowtofaq]

Could you please add this to the documentation (README.md#pool), to help future
users avoid hair loss trying to understand why the pool is stopping in the middle of execution!!

To see exceptions in threads (in case of buggy code) add the following in the beginning of your code

Thread::Pool.abort_on_exception = true

TY!

[nspence]

This would have saved me time, please do add it.

[run27017]

However, if I add it, the program will not abort when encounter an exception.

[tdxius]

You need to add the code below to get some kind of output of the exception.

pool.process do
  run_process
rescue Exception => reason
  puts reason
end