Gem::Commands::RebuildCommand#error_message

# File tmp/rubies/ruby-3.4.1/lib/rubygems/commands/rebuild_command.rb, line 227
def error_message(gem_name)
  if gem_name
    "Couldn't find a gemspec file matching '#{gem_name}' in #{Dir.pwd}"
  else
    "Couldn't find a gemspec file in #{Dir.pwd}"
  end
end