If select stop option in "stop build" and 2nd time click on "stop build" the "stop" option still available should be disabled and only option available should be "force stop"
http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=52e0be44e068b53959d9566516486b758be718dc
Verified against latest poky master commit 2fa1f7de3204ef370f2143eb4b8696de30c58a39