I'm currently bisecting, but this is a FYI (in case it's obvious to anybody)
That check was separated out from a larger test so we could put skipIfLinux around it (in r327977). I’m not sure why it’s failing, but it’s probably some silly typo. Unfortunately I don’t have time to look at it today.
I am hoping that the fix is obvious. If it’s not, you can revert that patch, and I’ll check it out tomorrow.