trace does not generate cover file #160524

import sys
import pprint
import trace

def func() -> None:
    print("Test")

if __name__ == '__main__':
    tracer = trace.Trace(count = 1, 
        trace = 0,
        countfuncs = 1,
        countcallers = 1)
    tracer.runfunc(func)
    r = tracer.results()
    r.write_results(show_missing=True, summary=True, coverdir=".")