OpenSprinkler › Forums › Third-Party Software › Help, can't get arduino to compile OS without errors… › Reply To: Help, can't get arduino to compile OS without errors…
I think v1.8 has different board definition file format. Basically, this is referring to step 4 of the built instructions for 2.x:
where you have downloaded the aopensprinkler.zip board profiles. You most likely need to open the boards.txt and add the missing build.board preferenc as the error message implies. You can take a look at the default arduino boards.txt to see examples of what build.board refers to.