Gem::Ext::Builder.ruby

# File tmp/rubies/ruby-4.0.0/lib/rubygems/ext/builder.rb, line 72
def self.ruby
  # Gem.ruby is quoted if it contains whitespace
  cmd = shellsplit(Gem.ruby)

  # This load_path is only needed when running rubygems test without a proper installation.
  # Prepending it in a normal installation will cause problem with order of $LOAD_PATH.
  # Therefore only add load_path if it is not present in the default $LOAD_PATH.
  load_path = File.expand_path("../..", __dir__)
  case load_path
  when RbConfig::CONFIG["sitelibdir"], RbConfig::CONFIG["vendorlibdir"], RbConfig::CONFIG["rubylibdir"]
    cmd
  else
    cmd << "-I#{load_path}"
  end
end