我一直在尝试将rails4和ruby 2.6.5版本部署到Heroku管道中。在发布步骤中出现以下错误。
错误跟踪

Running release command...
bundler: failed to load command: rake (/app/vendor/bundle/ruby/2.6.0/bin/rake)
LoadError: library not found for class Digest::SHA1 -- digest/sha1
  /app/vendor/ruby-2.6.5/lib/ruby/2.6.0/digest.rb:16:in `const_missing'
  /app/vendor/ruby-2.6.5/lib/ruby/2.6.0/digest.rb:100:in `block in Digest'
  /app/vendor/ruby-2.6.5/lib/ruby/2.6.0/digest.rb:98:in `synchronize'
  /app/vendor/ruby-2.6.5/lib/ruby/2.6.0/digest.rb:98:in `Digest'
  ...........