Errors - New to Roots sage, Trellis and Bedrock

[knowler]

This sounds a lot like this issue. Try the solution provided here:

[WIN 10] Install hangs at task Wordpress install: Install dependencies with Composer

I fixed this on OSX by downgrading Vagrant to 2.1.1. There must be a compatibility issue with Vagrant 2.2.1. Use your respective package manager/install system to downgrade to a previous release.