No fans were active until the sim started. Every time the sim is up the MacBook chokes. This has been the case since Xcode 6/7.
Xcode Version 11.0 (11A419c)
Open blank project / no other apps running.
10.15.1 Beta (19B77a)
MacBook Pro (Retina, 15-inch, Mid 2014)
16 GB 1600 MHz DDR3
NVIDIA GeForce GT 750M 2 GB
Xcode Version 11.0 (11A419c)
Open blank project / no other apps running.
10.15.1 Beta (19B77a)
MacBook Pro (Retina, 15-inch, Mid 2014)
16 GB 1600 MHz DDR3
NVIDIA GeForce GT 750M 2 GB