"Rebuilding all" when no build options changed

[whyameye]

Basic Infos

Hardware

Hardware: ESP-12F
Core Version: master Nov 2017
Arduino IDE 1.8.5 (OSX High Sierra)

Description

I often get the message "Build options changed. Rebuilding all" when literally not a single line of code has changed. And, based on the speed of compile, it is definitely rebuilding all, as promised.

I'm not sure if this is an Arduino IDE bug or an ESP8266 Arduino core bug so if I'm way off posting this here, apologies. :-)

Settings in IDE

Module: Generic ESP8266 Module
Flash Size: 4MB/1MB SPIFFS
CPU Frequency: 80Mhz
Flash Mode: DIO
Flash Frequency: 40Mhz
Upload Using: SERIAL
Reset Method: ck

[devyte]

I believe this is an Arduino IDE thing. If you so much as change a space in the .ino, or change the file timestamp somehow, even without any changes, it rebuilds everything.
Closing as OT.

[whyameye]

It could be an Arduino IDE thing, but it isn't me changing a space or a timestamp. I can click "Verify" then click on it immediately again as soon as it is finished and it happens. I had wondered if it could be related to boards.txt as I grabbed that file from #3722 and the problem showed up soon after that. I probably should have mentioned that in the OP. I've used the Arduino environment a fair amount and this is new behavior.

[d-a-v]

@whyameye here is the link for the previous boards.txt if you want to try it and check if your problem appeared with the new version.
I also experienced this but not always, and by reading this link we may have the beginning of an explanation (I sometimes compile modified examples without saving them).

[d-a-v]

@whyameye you are right. Same behaviour here. Using the old boards.txt make this problem disappear.

[whyameye]

this problem seems to go away with Arduino IDE 1.9.0 Beta.

[d-a-v]

@whyameye yes, it does, thanks!
Unfortunately, this beta version currently breaks our OOM debug checker...

[devyte]

@d-a-v any idea why it breaks?

[d-a-v]

The new architecture does not cope well with gcc cmdline -include option. This is fine now with #4357.
arduino-1.9 works far faster here than 1.8 when it comes to decide if something has to be rebuilt. I can't say if it does it right though :)

[d-a-v]

@whyameye if arduino-1.9-beta is OK for you, can we close here ?