Ruby 3.0.0 throwing NameError (uninitialized constant Boolean)

September 2, 2022

Literally, this is showing up in irb and in my application code. Suddenly ruby 3.0.0 is no longer recognizing Boolean

This worked a few weeks ago, it must have appeared after an OS update

$ irb
3.0.0 :001 > String
 => String 
3.0.0 :002 > Boolean
Traceback (most recent call last):
        4: from /Users/aronlilland/.rvm/rubies/ruby-3.0.0/bin/irb:23:in `<main>'
        3: from /Users/aronlilland/.rvm/rubies/ruby-3.0.0/bin/irb:23:in `load'
        2: from /Users/aronlilland/.rvm/rubies/ruby-3.0.0/lib/ruby/gems/3.0.0/gems/irb-1.3.0/exe/irb:11:in `<top (required)>'
        1: from (irb):2:in `<main>'
NameError (uninitialized constant Boolean)

env

ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin21]
rvm 1.29.12 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
MacOS 12.5.1 (2.4 GHz 8-Core Intel Core i9 processor)

Troubleshooting steps already taken:

uninstalled and reinstalled using RVM rvm uninstall 3.0.0 then rvm install 3.0.0

>Solution :

Ruby has never had a Boolean type. The Boolean constants true and false are, respectively, of types TrueClass and FalseClass, and both inherit directly from Object. There is not, and has never been, a type called Boolean in core Ruby.