Sketch always rebuilded

[Testato]

on IDE 1.6.8, win7_64, at every Verification in the consolle appear:

• Build options changed, rebuilding

This made the verification rpocess very slow

[Testato]

Test the bug in this way:

• Open Arduino IDE, it will open on empty sketch whit setup() and loop()
• add a simply space in the loop function
• press Verify

the "Build options changed, rebuilding" will writed in the consolle and the verification process is slow.
If you try to verify a second time, the "Build options changed, rebuilding" message always return

[PaoloP74]

👍

[facchinm]

should be solved by arduino/arduino-builder#129 , please test the nightly to check if the fix behaves correctly

[Testato]

it seems to work