Code review comment for lp:~pundiramit/linaro-android-build-tools/labt

This is a bit confusing. We require SOURCE_OVERLAY to be set (this was a recent change, so that's perhaps why it feels like a regression), for BUILD-INFO.txt file to be generated. Otherwise, someone can circum-vent our protection mechanisms (and more likely, build results will simply be inaccessible).

Then, this branch also deals with access to private repositories, but I am not sure I understand exactly what's going on. Can you please clarify the rationale for the changes?