Thanks for the report, Wenji. Please work with Denys to make sure these problems are represented in the ptrace-tests suite and update the utrace/tests wiki page. Note the current code has some existing regressions in ptrace-tests. It's possible what your tests check is already being checked by something in the suite. Having related similar tests or redundancies is fine, but it's most helpful if every test in the suite is as concise as it can be, to help focus the bug hunting.
Thanks, Roland
