twitter_oauth_bug.rb

require 'oauth'
 
consumer = {
  key: YOUR_CONSUMER_KEY,
  secret: YOUR_CONSUMER_SECRET
}
 
consumer = OAuth::Consumer.new(
  consumer[:key],
  consumer[:secret],
  site: 'https://api.twitter.com'
)
 
request_token = consumer.get_request_token(oauth_callback: YOUR_CALLBACK_URL)
`open "#{request_token.authorize_url}"`
 
print "OAuth Verifier: "
verifier = gets.chomp!
 
request_token = OAuth::RequestToken.new(
  consumer,
  request_token.token,
  # request_token.secret # NOTE: even commented-out this line, you get access token successfully.
)
access_token = request_token.get_access_token(oauth_verifier: verifier)
 
p access_token