These issues (allow updates within limits) are what I understand as the point of dependency resolution, I'm trying to understand how you do without it. In such

These issues (allow updates within limits) are what I understand as the point of dependency resolution, I'm trying to understand how you do without it. In such a case e.g. nixpkgs makes two attributes: a_1 and a_2 (and alias a to a_2). Packages that still require A 1.x will have a_1 as one of their dependencies, the rest a. This is avoided as much as possible, but is sometimes necessary. Common examples are Gtk 2 applications or C/C++ applications that can only be built against a Python 2 interpreter.