[m-rev.] for post-commit review: fix mmc_make test case failures

[Peter Wang]

On Fri, 28 Mar 2025 11:16:57 +1100 "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> For review by anyone.
> 
> BTW, I could not verify in which grades these test cases used to fail,
> because the web server on testing.mercurylang.org is unresponsive.
> (A ping does get returned, so the OS is alive.) Does anyone know
> what is causing that?

The server instance has been down for a few months, not sure what
happened. The IP address has likely been reassigned by now.
I'll let you know if/when we get a new instance up and running
somewhere.

Peter