If you care about the _exact version you are pinning_ (even though you will guarantee the pin between team members without needing to do this step), you can either pin nixpkgs repo to the state that had that version, source the target version directly, or for some ecosystems (eg ruby) you can just specify a version with a number and it has tooling to resolve that using "traditional" approaches.
In general though when working on a team, you dont really care about the _exact semver version_, you care about the major and handle version bumps by bumping the pin of nix packages.
In general though when working on a team, you dont really care about the _exact semver version_, you care about the major and handle version bumps by bumping the pin of nix packages.