Bundler error when trying to run a new bundle gem? undefined method `prefer_gems_rb?'

Question

So, I ran bundle gem cgscraper to auto build the directories for my project. However, when trying to run it in the CLI, I'm getting this error: undefined methodprefer_gems_rb?'`.

Full output:

~/code/projects/cgscraper on  master ✚
> ruby bin/console
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/rubygems_integration.rb:8: warning: already initialized constant Bundler::RubygemsIntegration::EXT_LOCK
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/rubygems_integration.rb:12: warning: previous definition of EXT_LOCK was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/version.rb:4: warning: already initialized constant Bundler::VERSION
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/version.rb:10: warning: previous definition of VERSION was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/constants.rb:4: warning: already initialized constant Bundler::WINDOWS
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/constants.rb:4: warning: previous definition of WINDOWS was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/constants.rb:5: warning: already initialized constant Bundler::FREEBSD
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/constants.rb:5: warning: previous definition of FREEBSD was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/constants.rb:6: warning: already initialized constant Bundler::NULL
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/constants.rb:6: warning: previous definition of NULL was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/current_ruby.rb:12: warning: already initialized constant Bundler::CurrentRuby::KNOWN_MINOR_VERSIONS
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/current_ruby.rb:12: warning: previous definition of KNOWN_MINOR_VERSIONS was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/current_ruby.rb:25: warning: already initialized constant Bundler::CurrentRuby::KNOWN_MAJOR_VERSIONS
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/current_ruby.rb:24: warning: previous definition of KNOWN_MAJOR_VERSIONS was here
/home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler/current_ruby.rb:27: warning: already initialized constant Bundler::CurrentRuby::KNOWN_PLATFORMS
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/current_ruby.rb:26: warning: previous definition of KNOWN_PLATFORMS was here
Traceback (most recent call last):
    8: from bin/console:3:in `<main>'
    7: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    6: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    5: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/setup.rb:10:in `<top (required)>'
    4: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler.rb:143:in `setup'
    3: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler.rb:195:in `definition'
    2: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/bundler-2.1.4/lib/bundler.rb:434:in `default_gemfile'
    1: from /home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/shared_helpers.rb:33:in `default_gemfile'
/home/noly/.rbenv/versions/2.6.1/lib/ruby/2.6.0/bundler/shared_helpers.rb:250:in `find_gemfile': undefined method `prefer_gems_rb?' for #<Bundler::FeatureFlag:0x000055661bb27790> (NoMethodError)

Anyone know what this is? I can't find anything about it on Google, and there's not a prefer_gems_rb method that I can see anywhere. This is just a default bundle gem project output that I tried to run.

Answer 1

I had the same problem. My ruby version was at 2.6.0. I updated my ruby version to 2.7.1 and reinstalled all of my gems. This fixed it. I hope this helps.