Just installed Arduino 1.6.9 Hourly Build 28 april 2016.
And now, the numbers compiling my 800 line sketch using 9 libraries:
- Full build : 35 secs
- No change Recompile : 11 secs
- Changed sketch Recompile : 11 secs
It seems like the slow "Changed Sketch Recompile" of 1.6.8 leading to a full build has been fixed.
I'm getting a little paranoid, so I re-checked Arduino 1.6.8 and the Changed sketch Recompile is still 35 secs.
But the compile times of Arduino 1.6.5 are still a lot faster.
I think I'll give the Hour Build 1.6.9 a try for a couple of days, instead of using 1.6.5.