Gem::Installer#ensure_loadable_spec

# File tmp/rubies/ruby-3.3.0/lib/rubygems/installer.rb, line 635
def ensure_loadable_spec
  ruby = spec.to_ruby_for_cache

  begin
    eval ruby
  rescue StandardError, SyntaxError => e
    raise Gem::InstallError,
          "The specification for #{spec.full_name} is corrupt (#{e.class})"
  end
end