error: anonymous function at /nix/store/xl229jfp80rpw7jymzaf87wsh4wylg28-source/default.nix:1:1 called with unexpected argument 'config'
at /nix/var/nix/profiles/per-user/root/channels/nixos/lib/modules.nix:519:8:
518| # works.
519| in f (args // extraArgs);
| ^
520|
How can I get the same effect using raw imports = [...] without channels?
Using fetchTarball pointing to a branch without pinning is even worse than channels. With channels, you still control when the source is bumped, even though the pinning is external to your configuration repository. If you just fetch a branch, it will update under your hands every time the cached version expires.