*** Update *** I have errors appearing in Eclipse showing red underlines and red x’s for pinMode and digitalWrite but the program builds without errors, flashes, and runs properly. Bewildering.
I’ve downloaded the device OS from git hub. Setup Eclipse to build it. It builds and flashes fine the word ‘test’ displaying in my serial terminal program.
When I try to do simple blinkie code i get errors like “invalid arguments candidates are void pinmode(?,?)…” Same odd errors on digitalWrite() etc.
Not an answer to your question, but have you heard about Particle Workbench (based on VSCode) which will be the new desktop IDE that also deals with all the download and setup tasks required to build Device OS and Application offline?
I've managed to setup Eclipse to build Device OS in the past, but switching target versions with it was just a PITA, but with PWB that's become a simple task of changing one switch and let the IDE do the rest.