problem with rake in Redpotion - Promotion on OSX Catalina 10.15.4

Question

I have the following errors running rake in RubyMotion, using Redpotion gem (promotion).

/usr/local/Cellar/ruby/2.7.1_2/lib/ruby/gems/2.7.0/gems/ProMotion-3.0.0/lib/ProMotion.rb:9:    warning: deprecated Object#=~ is called on Array; it always returns nil
/usr/local/Cellar/ruby/2.7.1_2/lib/ruby/gems/2.7.0/gems/ProMotion-3.0.0/lib/ProMotion.rb:9: warning: deprecated Object#=~ is called on Array; it always returns nil
rake aborted!
NoMethodError: undefined method `new' for BigDecimal:Class
/Users/username/Documents/ruby-projects/ipu/my_new_app/Rakefile:7:in `<top (required)>'
(See full trace by running task with --trace)

Rakefile:7 Bundler.require

/usr/local/Cellar/ruby/2.7.1_2/lib/ruby/gems/2.7.0/gems/ProMotion-3.0.0/lib/ProMotion.rb:9 insert_point = app.files.find_index { |file| file =~ /^(?:./)?app// } || 0

how can I resolve this error? my dev environment details ruby 2.7.1p83 rubyMotion 7.4 RedPotion 1.7.1 OS = MAC OSX Catalina 10.15.4

I still havent had any help yet. Is there anyone that can give me some hints with this problem please.

Answer 1

The gem was most likely built using the system Ruby, which is earlier than 2.7 (Mojave is 2.3.7 and Catalina is 2.6.3). Since the Ruby 2.7 BigDecimal class doesn't have a new method (your NoMethodError), you can use the system Ruby, or a version that matches it if using a version manager.