After bug 1593465 lands, we'll get crash logs for failed PGO run tasks using mozcrash. Unlike in test runs however, for some reason the Windows stacktrace has double newlines for the output from minidump_stackwalk. Here's some background info from that bug:

https://bugzilla.mozilla.org/show_bug.cgi?id=1593465#c19

The difference between PGO runs & test runs is likely that the test harness uses MessageLogger() to handle the output, while the PGO run simply uses print(). However, my attempts to use MessageLogger() didn't fix the issue. This may be as easy as adding universal_newlines=True to the minidump_stackwalk invocation, but that would require verifying that it does not mess up the output of a test crash.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.