Pass arguments to nixpkgs package

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1

Packages in nixpkgs often have arguments with default values, for example

If I use such a package (in a flake, in case it makes any difference) thus

packages = [
    pkgs.geant4
];

but would like to override some of those defaults, how would this be done?

2

usually like this:

packages = [
    (pkgs.geant4.override { enableQT = true; /* etc */ })`
];