```ruby
module Export
  module Base
    private

    def Base.export(sql, basename)
      # remove any existing tmp file
      path = Base.tmp_path basename
      path.unlink if path.exist?
      path.dirname.mkdir_p unless path.dirname.exist?
      FileUtils.chmod 0777, path.dirname

      # ensure the /public/export directory exists
      target = Base.public_path basename
      target.dirname.mkdir unless target.dirname.exist?

      # dump to csv and move to /public/export
      ActiveRecord::Base.connection.execute(sql % path)
      path.rename target
    end

    def Base.tmp_path(basename)
      Pathname.new File.join("#{Rails.root}/tmp/export", basename)
    end

    def Base.public_path(basename)
      Pathname.new File.join(RAILS_ROOT, "public", "export", basename)
    end
  end
end
```

Use FileUtils, not Pathname to create export dirs
user
```ruby
module Export
  module Base
    private

    def Base.export(sql, basename)
      # remove any existing tmp file
      path = Base.tmp_path basename
      path.unlink if path.exist?
      FileUtils.mkdir_p path.dirname unless path.dirname.exist?
      FileUtils.chmod 0777, path.dirname

      # ensure the /public/export directory exists
      target = Base.public_path basename
      target.dirname.mkdir unless target.dirname.exist?

      # dump to csv and move to /public/export
      ActiveRecord::Base.connection.execute(sql % path)
      path.rename target
    end

    def Base.tmp_path(basename)
      Pathname.new File.join("#{Rails.root}/tmp/export", basename)
    end

    def Base.public_path(basename)
      Pathname.new File.join(RAILS_ROOT, "public", "export", basename)
    end
  end
end
```
assistant