```
nix-repl> (pkgs.htop.overrideAttrs { pname = "hello-overriden"; }).pname
error:
… while evaluating a branch condition
at /nix/store/phn5cahwacv9wjgalygw62x8l4xbl6x3-source/lib/customisation.nix:86:7:
85| in
86| if builtins.isAttrs result then
| ^
87| result // {
… while calling the 'isAttrs' builtin
at /nix/store/phn5cahwacv9wjgalygw62x8l4xbl6x3-source/lib/customisation.nix:86:10:
85| in
86| if builtins.isAttrs result then
| ^
87| result // {
(stack trace truncated; use '--show-trace' to show the full trace)
error: attempt to call something which is not a function but a set
at /nix/store/phn5cahwacv9wjgalygw62x8l4xbl6x3-source/pkgs/stdenv/generic/make-derivation.nix:58:21:
57| f = self: super:
58| let x = f0 super;
| ^
59| in
```