[Nix-dev] freezing current version of a package

[Sergey Mironov]

Hi. Common usecase:

nix-channel --update nixos

breaks some package which was installed via configuration.nix.
If I remove the package from configuration, system will update
successfully, but I really need this package right now. Is it possible
to somehow 'move' the package and it's deps to the per-user category
(aka nix-en v -i) instead of removing it completely?

Sergey