Building from source on Windows

[MoonlightSentinel]

On Saturday, 29 January 2022 at 07:41:02 UTC, forkit wrote:
> [...]
> C:\source\D\druntime>make -f win64.mak
> "make" -f mak/WINDOWS import 
> DMD="..\dmd\generated\windows\release\64\dmd" HOST_DMD="dmd" 
> MODEL=64 IMPDIR="import"
> ..\dmd\generated\windows\release\64\dmd -conf= -c -o- -Isrc 
> -Iimport -Hfimport\core\sync\barrier.di src\core\sync\barrier.d
> 34 modules passed unittests
> [...]

You apparently built dmd with unittests enabled. D applications 
build with `-unittest` do snot execute the actual main unless 
explicitly requested via a Druntime option. So the targets of the 
make rule are never built, causing the cascading error later on 
for `copydir`.

Not sure how you build that dmd since `make` / `build.d` 
explicitly use a different name for the unittest executable.