How to unit-test a phobos module?

[Q. Schroll]

On Thursday, 26 November 2020 at 05:29:16 UTC, Mike Parker wrote:
> On Wednesday, 25 November 2020 at 21:36:36 UTC, Q. Schroll 
> wrote:
>
>>
>> [1] https://wiki.dlang.org/Building_under_Windows
>
> You might try Digger. That will hide all the tedious bits.
>
> https://code.dlang.org/packages/digger

I think using digger in principle works and I assume the problems 
I got aren't Digger's fault, but ae's. Building DMD + DRuntime 
failed.

In my working folder (created by DUB running Digger), there's 
DMD.exe, but trying compiling anything results in "Error: cannot 
find source code for runtime library file 'object.d'"

I did nothing but follow the instructions on 
code.dlang.org/packages/digger :

dub fetch digger
dub run digger -- build

I tried building the current version v2.94.2 and tried 
--model=64, nothing helped.

The error I'm presented is when

>    work\build\bin\dmd.exe -lib -ofphobos64.lib -Xfphobos.json 
> -conf= -m64 [..1]
>        -I../druntime\import std\stdio.d [..2]

is executed.
[..1] IMO unrelated options
[..2] following many more std modules, probably all that there 
are (haven't checked)

The error message is:
> std\stdio.d(16): Error: module stddef is in file 
> 'core\stdc\stddef.d' which cannot be read

I have no idea why the import failed. The stdc subfolder isn't in 
the core folder, but that core folder isn't even in a 
druntime/import folder anyway. Something's going horribly wrong.

It seems something beyond us just doesn't want me to get D stuff 
done. :(

Tomorrow, I'll try setting up a dual boot and give it a shot 
there. (Not the dub experience  but following 
https://wiki.dlang.org/Building_under_Posix)

Thank you all for your answers.