Naive packaging in GitHub repo, how to pick up changes

At work we have a few repos on GitHub with utility scripts. I made a naive attempt at packaging them by sticking a default.nix in the root. Something like

{pkgs ? import <nixpkgs> {}}:

with pkgs;

  work-helpers = stdenv.mkDerivation {
    name = "work-helpers";
    src = lib.cleanSource ./.;
    buildPhase = ''
    installPhase = ''
      install -D -m 755 ./tool-1 "$out/bin/tool-1"
      install -D -m 755 ./tool-2 "$out/bin/tool-2"
      install -D -m 755 ./tool-3 "$out/bin/tool-3"

Then I added the repo as a channel using nix-channel. That works as expected.

Then I realised that this doesn’t pick up changes pushed to the repo, nix-channel --update works of course, but a subsequent nix-env --upgrade won’t build a new version incorporating the pushed changes to the scripts.

If I want to remedy this, i.e. to make nix-env --upgrade pick up that the scripts have been modified and build a new package, what are my options?

You’ll probably want to use --leq with nix-env --upgrade since your derivation name does not include a version.