Couldn't parse cron string

[thestelz]

We just updated to rails 5.2.2 and ruby 2.5.3 from rails 4.1.7 and ruby 2.1.2. When the whenever --update-crontab command is ran, we get the following error:

$ whenever --update-crontab
Traceback (most recent call last):
	24: from /home/ubuntu/.rvm/gems/ruby-2.5.3/bin/ruby_executable_hooks:24:in `<main>'
	23: from /home/ubuntu/.rvm/gems/ruby-2.5.3/bin/ruby_executable_hooks:24:in `eval'
	22: from /home/ubuntu/.rvm/gems/ruby-2.5.3/bin/whenever:23:in `<main>'
	21: from /home/ubuntu/.rvm/gems/ruby-2.5.3/bin/whenever:23:in `load'
	20: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/bin/whenever:44:in `<top (required)>'
	19: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/command_line.rb:6:in `execute'
	18: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/command_line.rb:38:in `run'
	17: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/command_line.rb:111:in `updated_crontab'
	16: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/command_line.rb:57:in `whenever_cron'
	15: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever.rb:12:in `cron'
	14: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:75:in `generate_cron_output'
	13: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:165:in `cron_jobs'
	12: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:165:in `each'
	11: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:166:in `block in cron_jobs'
	10: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:141:in `cron_jobs_of_time'
	 9: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:141:in `each'
	 8: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/job_list.rb:145:in `block in cron_jobs_of_time'
	 7: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:38:in `output'
	 6: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:38:in `each'
	 5: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:39:in `block in output'
	 4: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:39:in `each'
	 3: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:40:in `block (2 levels) in output'
	 2: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:46:in `output'
	 1: from /home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:54:in `time_in_cron_syntax'
/home/ubuntu/.rvm/gems/ruby-2.5.3/gems/whenever-0.10.0/lib/whenever/cron.rb:154:in `parse_as_string': Couldn't parse: 0 2 20 3 (ArgumentError)

The line that it's failing on is:

every '0 2 20 3,6,9,12 * ' do
    rake 'db:generate_new_quarter'
end

We haven't changed that line since 2013. Is there something that we need to configure on our end or is this a bug?

Not sure if this is a duplicate of #766, so I created a new issue instead. Figured you guys would know best.

Thanks!

[thestelz]

Even tho the line hasn't changed since 2013, removing any trailing spaces fixed the issue.

-every '0 2 20 3,6,9,12 * ' do
+every '0 2 20 3,6,9,12 *' do

Closing this, but not sure if something changed in ruby or rails to start causing this to fail.