jquery/jquery-ui — comment on commit b7df9e45cdce8846080528e31059700a9001b6f0
File: ui/jquery.ui.selectmenu.js line 146
By rdworth:

One of the common widget unit tests is that all widgets should be able to be initialized based on their default element and using default options (no options passed to init). This failure minimizes down to

$( "" ).appendTo( "body" ).selectmenu()

notice it's because the select (the default element for selectmenu) has no options. So this would pass

$( "
" ).appendTo( "body" ).selectmenu()

but the former needs to pass as well.