Recommendation for a D build system

["Luís]

I have some old D code and I wanted to improve its build system: 
that code was using a .bat and shell script with dmd, manually 
listing all the .d files to be linked! Don't ask me why I didn't 
use at least a Makefile, I don't recall, this is quite old code.

What would you currently recommend to build a not very big D 
codebase?

(if you use just dmd / rdmd, to not depend on another tool, *how* 
do you use it?)

--
Luís