Actually build hangs on 'assemble-contrib-anchors' plugin. If we remove it then build succeded.
Windows 7 x64
Sounds like this is an issue from when we were trying to upgrade plugins/middleware to a newer version of assemble that wasn't released yet.
Try changing the version in the package.json from assemble-contrib-anchors: '*' to assemble-contrib-anchors: '~0.1.0' and re-run npm i. You might have to clear your cache npm cache clear first.
npm cache clear
Removing all the contrib versions and replacing them with the middleware versions appears to work:
Change assemble modules from contrib to middleware. Fixes #52