help: differentiating between packages on update/upgrade [what is in the ()'s]

[truesilver92]

running nox chromium

returns many results, but the keys ones are here:

1 chromium-83.0.4103.61 (nixpkgs.chromium)
    An open source web browser from Google
20 chromium-81.0.4044.122 (nixpkgs.ungoogled-chromium)
    An open source web browser from Google, with dependencies on Google web services removed

I installed the nixpkgs.ungoogled-chromium one. When trying to do updates I run nix-env -u, and nix tries to replace nixpkgs.ungoogled-chromium with nixpkgs.chromium. How do I lock the install to a specific provider? (not sure what you call the package name inside the ()'s). I don't think this is a nox specific issue, but I don't even know what to google or look through on the nix manual.

Summary of questions:

Why does chromium get auto-upgraded to a different package?

How do I lock it to only nixpkgs.ungoogled-chromium?

What do you call the part of the package name inside of the ()'s?

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I am using Arch Linux (Manjaro) with the nix daemon

[truesilver92]

My current thinking is that adding the package manually using my ~/.config/nixpkgs/config.nix file may be a way to do it. It seems more tedious, but if it works then it works.

[truesilver92]

Same question here

[truesilver92]

I think that the part in ()'s is the attribute path, but how do you get nix-env -u to stick with a specific attribute path?