Backstory: when Botond tried landing bug 1611660, it caused a spike in win7 mingw reftest timeouts. See bug 1611660 comment 40 for a sample try push. I've been doing try pushes with additional logging to track this down, and the timeouts are caused by the content process simply hanging at various points. I've done many try pushes with lots of printfs to bisect exactly where the hangs are.

This bug is specifically about the content process hanging at this block of code, presumably in the _wfopen call. See e.g. the output in this try push where the last line logged comes from this printf and the next one a few lines down (after the _wfopen call) doesn't show up in the log.

I'll be filing other bugs for other hang points as I identify them.

Not sure if this is still an issue, but that _wfopen call is debug-only (it's in refcount tracing), so marking as S3.

Actually, WONTFIX, as it's unlikely we'll get to this while win7 remains supported, and debug builds on win7 are likely vanishingly uncommon.