What is up with building DMD (et al.) on Windows?

[Jeremy DeHaan via Digitalmars-d-learn]

On Wednesday, 11 May 2016 at 14:30:44 UTC, Vladimir Panteleev 
wrote:
> On Tuesday, 10 May 2016 at 04:48:23 UTC, Jeremy DeHaan wrote:
>> Building DMD, Phobos, and druntime on Linux is so easy and 
>> straight forward. It all works as expected. What's up with 
>> building DMD on Windows?
>
> For historical reasons, the Windows makefiles take a different 
> approach in many aspects. One important point is that they are 
> limited to the feature set of the Digital Mars make 
> implementation, which is extremely basic.

There is one thing that I don't understand about the Windows 
makefiles though. The Posix makefiles for druntime and phobos use 
the dmd executable found in dmd/src/ and that makes sense. It is 
the one you should be using. That is not the case for the Windows 
makefiles though. It uses the one found on PATH even though it 
would be easy to do the same as the Posix version. Why is that?