I have hunted around for this, but no luck. If a build fails, there is a note about using -j1 (that makes sense!), and V=s or V=sc to debug. It works, but ... what does this mean exactly? I have tried to find it, but no luck. Just not sure what all the options are (for V in particular).
No worries (URL only) ... and apologies. I really did try that (exact) search. No idea how I missed it, but I won't try to say I didn't ... cuz clearly I did!
Idle curiosity in my case, never a burning desire to understand it. The opportunity to pile my question onto this one was there so i took it thanks for the link.