@satendra4u, not sure why you’d get that unless maybe you compiled from the main folder. Make sure you follow the instructions to run make… etc from the modules folder. Are you compiling from develop? I recently found it wouldn’t compile at all on develop, had to go back to v0.4.9
EDIT: Scratch that about the develop branch. I misspoke. I had that issue w/ a photon compile, not w/ electron. Received compile error: …/…/…/build/target/system/platform-6-m/\libsystem.a(system_sleep.o): In function CloudClass::process()': C:\particle\develop\system/../wiring/inc/spark_wiring_cloud.h:299: undefined reference toApplicationWatchdog::last_checkin’
I wasn’t even using sleep in that photon app. There might currently be a temporary issue in the develop branch.
EDIT2: electron stop mode sleep app just compiled fine for me in develop branch. Only get the problem w/ a photon.