I try to upgrade a nodebb instance from some 1.2.x version to the latest (1.4.2 I think)
16/1 12:19:43  - info: [upgrade] Schema update complete!
16/1 12:19:43  - info: [build] Building client-side CSS
16/1 12:19:57  - info: [build] js => Completed in 14.563s
At this point the scripts hangs indefinitely, using no CPU time...
The upgrade can be aborted using ctrl-c, the resulting installation is unusable.
nodejs is version 4.7.2 from the nodesource distribution, on a Centos 6 server.