Please take a look at this original report: https://clusterfuzz.com/v2/testcase-detail/4612142496743424?noredirect=1

It fails to reproduce:
[2018-09-21 05:16:06 UTC] clusterfuzz-linux-high-end-c5m2: Regression task errored out: Known crash revision 56063 did not crash.

Locally, it fails reliably though. I uploaded it as a new job: https://clusterfuzz.com/v2/testcase-detail/6242564284612608?noredirect=1
And now it's reproducible, and creates a regression range.

I am wondering what was wrong in the original test case that it didn't reproduce. Unfortunately, it does not show the flags used to reproduce.