Ui-bootstrap tooltip not working when used with ng-repeat

I would like to use a directive ui-bootstrap tooltip

to assign tooltips to an array of buttons that are rendered using a directive ng-repeat

, for example:

<button ng-repeat="label in labels" tooltip="{{label}}">{{label}}</button>

      

        
        
        
      

    

but I got a weird problem: the ng-repeat loop variable gets empty except in the tooltip itself, so for example in the above example the label value will be empty in the button. A snippet showing this issue can be seen at this link . All right removes the tooltip attribute. Is there anyone who uses ui-bootstrap and knows about issues like this?