Getting WeakRef::RefError: Invalid Reference - probably recycled error

[ashrafuzzaman]

require 'less'
path = '/home/jitu/projects/etc/eventpage/public/themes/event/freelancer/less'
parser = Less::Parser.new :paths => [path], :filename => 'freelancer.less'

This code throws me the following error,

WeakRef::RefError: Invalid Reference - probably recycled
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `inspect'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:109:in `block in <module:IRB>'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/inspector.rb:102:in `inspect_value'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/context.rb:385:in `inspect_last_value'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:665:in `output_value'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:494:in `block (2 levels) in eval_input'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:627:in `signal_status'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:490:in `block in eval_input'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/ruby-lex.rb:246:in `block (2 levels) in each_top_level_statement'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/ruby-lex.rb:232:in `loop'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/ruby-lex.rb:232:in `block in each_top_level_statement'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/ruby-lex.rb:231:in `catch'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb/ruby-lex.rb:231:in `each_top_level_statement'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:489:in `eval_input'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:430:in `block in run'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:429:in `catch'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:429:in `run'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/lib/ruby/2.4.0/irb.rb:385:in `start'
	from /home/jitu/.rvm/rubies/ruby-2.4.1/bin/irb:11:in `<main>'

What am I doing wrong? I want to compile less files in a directory dynamically.