Lars Schneider [off-list ref] writes:
The difference between Travis and my machine is that I changed the
default shell to ZSH with a few plugins [1]. If I run the test with
plain BASH on my Mac then I can reproduce the test failure. Therefore,
we might want to adjust the commit message if anyone else can reproduce
the problem on a Mac.
With "Reportedly macOS does this, at least in the Travis builds.",
even with the result from you in your follow-up message to the
message I am responding to, I think what Peff wrote in the log
message is good enough.
Thanks for digging, and thanks Peff for coming up the workaround.