Recompile with -Xlint "note" (android astc project)

Hi
I am trying to create a test empty package for Google Cardboard and have followed the step by step guide here: https://docs.unrealengine.com/en-us/Platforms/GoogleVR/QuickStart

I have got as far as section 3 of this guide, but when I try to package the project i hit problems. I have left it for 12 hours and still not got to the end. It seems to stop at a
note: recompile with ~Xlint although it is so slow, it might still be doing something; impossible to tell!

Any idea what I can do to get to the end of the packaging stage within 15 hours since it is a fairly old machine that gets pretty hot and am paranoid about leaving it working overnight!

thanks

3rd time lucky! Has completed this time; only difference was i re-ran it having cancelled. The second time I deleted and started again

3rd time lucky! Has completed this time; only difference was i re-ran it having cancelled. The second time I deleted and started again