I have been using Octopus to deploy ARM templates for a while now and the default task that comes with Octopus to deploy doesn't have any debugging information enabled and when you run this powershell:
New-AzureRMResourceGroupDeployment
If you don't have debugging information enabled, the output of a failed deployment is basically “Deployment Failed, suck it up dude” or something along those lines.
If you want to find out why your deployment failed, the best thing to do is grab your template and parameter file and run: