They're not testing for GCC stalling, they're testing for user interaction stalling -- the same thing the OP is complaining about. Strictly speaking, the direc

They're not testing for GCC stalling, they're testing for user interaction stalling -- the same thing the OP is complaining about. Strictly speaking, the direct cause of OP's problem appears to be outside the kernel, but it is system-level. Microsoft has created a stack in which low-priority tasks can trivially destroy the responsiveness of interactive tasks unrelated to the build process.