[AceJohnny2]

I have! Tup was high on my list of potential replacement candidates (despite being initially put-off by the cheekiness of its homepage).

In my experiments though, Tup failed hard on point 2, lacking a good language to factorize the dependency graph declaration. (and to be clear, I think Make's is pretty terrible by itself, before GMSL or Guile extensions come into the picture)

Edit: I see tup supports Lua extensions, which may cancel my complaint above.