Pikaday is not defined

I'm getting the following error when I am using gitlab on master

Uncaught ReferenceError: Pikaday is not defined
    at DueDateSelect.initDatePicker (due_date_select.js?53ca:49)
    at new DueDateSelect (due_date_select.js?53ca:30)
    at HTMLButtonElement.eval (due_date_select.js?53ca:200)
    at Function.each (jquery.js?8616:360)
    at jQuery.fn.init.each (jquery.js?8616:137)
    at DueDateSelectors.initIssuableSelect (due_date_select.js?53ca:198)
    at new DueDateSelectors (due_date_select.js?53ca:166)
    at __webpack_exports__.a (init_issuable_sidebar.js?3c85:16)
    at Dispatcher.initPageScripts (dispatcher.js?5952:172)
    at new Dispatcher (dispatcher.js?5952:87)

Posted in frontend slack channel but creating this issue to track the progress. @timzallmann believes it is probably related to the deferred loading work that was recently merged