Seems like building bundles is broken (again) in Plone 5.2
For me, the building just 'keeps on forever'
Probably due to a javascript error: TypeError: undefined is not an object (evaluating 't.window.requirejs.optimize')
Espen, you know you need to provide more detail... Is this on Python 2 or 3? What is in the bundle? What is in your browser console? (the full error stack)
After running Upgrade-Steps from 5.1.5 to 5.2 under py2, i have seen this today. I import the profile with id: "profile-Products.CMFPlone:dependencies" via portal_setup in the zmi and all was fine.