samuel@aiko ~/P/r/rack-session (modernize-gem)> chruby jruby
samuel@aiko ~/P/r/rack-session (modernize-gem)> irb
irb(main):001:0> RUBY_VERSION
=> "3.1.0"
irb(main):002:0> RUBY_PLATFORM
=> "java"
irb(main):003:0> Dir["*", "*"]
=> 
["Rakefile",                         
 "config",                           
 "gems.locked",                      
 "gems.rb",                          
 "lib",                              
 "license.md",                       
 "pkg",                              
 "rack-session.gemspec",             
 "readme.md",                        
 "release.cert",                     
 "security.md",                      
 "Rakefile",                         
 "config",
 "gems.locked",
 "gems.rb",
 "lib",
 "license.md",
 "pkg",
 "rack-session.gemspec",
 "readme.md",
 "release.cert",
 "security.md"]
irb(main):004:0> Dir["*", "*", base: "."]
org/jruby/RubyDir.java:278:in `[]': no implicit conversion of String into Integer (TypeError)
        from (irb):4:in `evaluate'         
        from org/jruby/RubyKernel.java:1143:in `eval'
        from org/jruby/RubyKernel.java:1586:in `loop'
        from org/jruby/RubyKernel.java:1292:in `catch'
	from org/jruby/RubyKernel.java:1292:in `catch'
	from /home/samuel/.rubies/jruby-9.4.0.0/lib/ruby/gems/shared/gems/irb-1.4.1/exe/irb:11:in `<main>'
	from org/jruby/RubyKernel.java:1091:in `load'
	from /home/samuel/.rubies/jruby-9.4.0.0/bin/irb:23:in `<main>'
irb(main):005:0> Dir["*", base: "."]
=> ["Rakefile", "config", "gems.locked", "gems.rb", "lib", "license.md", "pkg", "rack-session.gemspec", "readme.md", "release.cert", "security.md"]

samuel@aiko ~/P/r/rack-session (modernize-gem)> chruby 2.7.7
samuel@aiko ~/P/r/rack-session (modernize-gem)> irb
irb(main):001:0> RUBY_VERSION
=> "2.7.7"
irb(main):002:0> RUBY_PLATFORM
=> "x86_64-linux"
irb(main):003:0> Dir["*", "*"]
=> 
["license.md",
 "lib",
 "gems.locked",
 "release.cert",
 "pkg",
 "rack-session.gemspec",
 "gems.rb",
 "security.md",
 "readme.md",
 "config",
 "Rakefile",
 "license.md",
 "lib",
 "gems.locked",
 "release.cert",
 "pkg",
 "rack-session.gemspec",
 "gems.rb",
 "security.md",
 "readme.md",
 "config",
 "Rakefile"]
irb(main):004:0> Dir["*", "*", base: "."]
=> 
["license.md",
 "lib",
 "gems.locked",
 "release.cert",
 "pkg",
 "rack-session.gemspec",
 "gems.rb",
 "security.md",
 "readme.md",
 "config",
 "Rakefile",
 "license.md",
 "lib",
 "gems.locked",
 "release.cert",
 "pkg",
 "rack-session.gemspec",
 "gems.rb",
 "security.md",
 "readme.md",
 "config",
 "Rakefile"]