Can't merge hierarchical options into submodule (or freeform option) #146882
Description
Describe the bug
Part of an option tree may be free-form.
Extending the free-form part in a separate module is hard and prevents certain use cases and migrations.
Steps To Reproduce
let
lib = import ./lib;
inherit (lib) types mkOption;
in
(lib.evalModules {
modules = [
{
options.free = mkOption {
type = lib.types.submoduleWith {
modules = [
# UPDATE: A freeformType is not necessarily part of the problem.
# { freeformType = lib.types.anything; }
];
};
default = {};
};
}
{
options.free = mkOption {
type = lib.types.submoduleWith {
modules = [
{
options.complicated = mkOption {
type = types.int;
default = 1;
};
}
];
};
};
}
{
options.free.specific = mkOption {
type = lib.types.int;
default = 2;
};
}
];
}).config$ nix-instantiate test.nix --eval --strict
error: The option `free' in `<unknown-file>' is a prefix of options in `<unknown-file>'.
(use '--show-trace' to show detailed location information)
The submodule only exists in order to provide a freeform type for that subtree, but it is conceptually still the same tree.
Expected behavior
$ nix-instantiate test.nix --eval --strict
{ free = { complicated = 1; specific = 2; }; }Additional context
A semi-workaround is to make writing the unnecessary module boundary easier.
mkSubmoduleOptions =
options:
mkOption {
type = types.submoduleWith {
modules = [ { inherit options; } ];
};
};
However, this is needlessly complicated and it does not help in situations where a freeform type is introduced in a decentralized scenario.
Notify maintainers
Metadata
Maintainer information:
# a list of nixpkgs attributes affected by the problem
attribute:
- lib.evalModules
- lib.mkOption
# a list of nixos modules affected by the problem
module: