What’s the difference with having a plain Makefile and running
shell nix-shell -p hello --run make?
You may mean something more ~functional, but: the main difference is having the dependencies explicitly recorded in the Makefile where others who check out a project can straightforwardly use it as long as they have Nix installed.
(I’m not sure you meant to copy the outer
shell; if you did, I may be misinterpreting you…)
On a related note: an official affordance here might be a nice UX win for developers. Maybe a
nix make that runs make targets with deps supplied–either imperatively or pulled from the shebang as in
Even if it’s just ~sugar.