> AFAIK, Just doesn't have any way to mark "this task is complete, so don't re-run it". It also doesn't have file-based dependendicies, which are pretty common for any kind of programming.

That's fair but also not what I'm looking for in a task runner, that's why I explicitly said "not a build tool", which to me this falls under (although I realize everybody has a different definition of these terms and where they draw the line if at all).