The addListener() polyfill on line 72 of picturefill/matchmedia.js on branch 7.x-1.x-dev is broken. IE9 and older complain that there is no Drupal.debounce function, which is true. Drupal 7 does not have that function, even though Drupal 8 does. IE9 then does not run any other javascript.
Closed: works as designed
2.0
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