In an automated build process, you always need logs as reference for troubleshooting because the task is scheduled and running under the context of a different user, so you won’t be able to see console output.
If you use MSBuild to run your build tasks, here is how to get it to write to a text file when it runs:
msbuild mybuildroutines.msbuild /p:Desitination=WebServer /t:DeployAndTestWebServerBuild /l:FileLogger,Microsoft.Build.Engine;logfile=c:\temp\DeployAndTestWebServerBuild.log
Thanks to Miles for discovering this incredibly useful feature.