Hi Sarah,

>> I set up a tmpfs file system at /tmp. And, curiously, now the package
>> builds successfully. No idea why this is happening, though.
>
> I actually just figured this out as well. You're on a rotational disk,
> aren't you?

Yep.

> Since nncp makes heavy use of the spool file (which I think
> it mocks in /tmp for testing), I think that's why your tests are taking
> so long and timing out. Tests complete for me on a SSD in ~40s. (All the
> error messages are red herrings; they're expected errors.) If this is
> the case, it might be worth it to increase the test timeout for those
> who use --no-substitutes.

Indeed, that makes sense! I have now disabled the timeout. Without a
tmpfs, the tests take ~47 minutes on my rotational disk, but they do
complete successfully.

>>>>>> Does CFGPATH need to be set?
>>>>>
>>>>> I have now set CFGPATH TO /etc/nncp.hjson.
>>>>
>>>> When I run any of the executables, I get:
>>>>
>>>> main.go:73: Error during initialization: stat /usr/local/etc/nncp.hjson:
>>>> no such file or directory

I fixed this as well. `go list` wasn't finding the correct module path,
and thus the correct cfgpath variable was not being set.

I'm sending a v3 of the patch. Let me know if everything looks good, and
I'll push. Thanks for the comprehensive review! :-) The package looks
much better now.

Regards,
Arun