Rufus scheduler debugging

Rufus scheduler debugging

I am doing this in my Rails console:
scheduler.at 1.minute.from_now do Service.log.debug 'scheduler works' end
scheduler is defined in other file:
require 'rubygems'
require 'rufus/scheduler'
def scheduler
@scheduler ||= Rufus::Scheduler.start_new
end
And when I run in console:
Service.log.debug 'scheduler works'
Service log file is written.
Problem
scheduler.at 1.minute.from_now do Service.log.debug 'scheduler works' end
Does not write in the log after a minute. What am I missing? How could I
debug this?