`require': Cannot load such file -- rdoc (LoadError)

Question

While trying to run the "irb", I ran into this error:

<internal:/usr/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require': cannot load such file -- rdoc (LoadError)

from

from <internal:/usr/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/lib/irb/input-method.rb:17:in `<top (required)>'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/lib/irb/context.rb:14:in `require_relative'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/lib/irb/context.rb:14:in `<top (required)>'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/lib/irb.rb:16:in `require_relative'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/lib/irb.rb:16:in `<top (required)>'
from <internal:/usr/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
from <internal:/usr/lib/ruby/3.0.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
from /usr/lib/ruby/gems/3.0.0/gems/irb-1.4.1/exe/irb:9:in `<top (required)>'
from /usr/bin/irb:25:in `load'
from /usr/bin/irb:25:in `<main>'

I tried downgrading the ruby version from 3.0.3 to 2.7, but didn't work; had the same error.

Answer 1

For me, running gem install rdoc did not work,so i added this to the Gemfile: gem "rdoc", require: false, then ran bundle install. That worked.