I’ve created simple dotnet core console app and bundled it into snap. The result is same - snap required process control. I created strace log for it.
As I understand from log, sched_setaffinity and sched_getaffinity are used to manipulate app’s process child processes created with clone() function - in other words threads. So CAP_SYS_NICE should not be required.
UPDATE: I’ve created issue on dotnet’s repo.