Marc, the memory invalid accesses are because you are enabling all probes and printing three parameters, but each probe actually has a different number of parameters and different meaning for them. Current version:

"""
provider python {
    probe function__entry(const char *, const char *, int);
    probe function__return(const char *, const char *, int);
    probe instance__new__start(const char *, const char *);
    probe instance__new__done(const char *, const char *);
    probe instance__delete__start(const char *, const char *);
    probe instance__delete__done(const char *, const char *);
    probe line(const char *, const char *, int);
    probe gc__start(int);
    probe gc__done(long);
};
"""

In particular, this explain the weirdness in your gc-start/gc-done probes.

Can you run the testsuite with "./python Lib/test/regrtest.py -v test_dtrace.py"?. The stack dump test will fail for sure, because MacOS DTrace port doesn't support uhelpers at all.

5AM here. Time for some sleep!.