JSON convert in modules error

[jd1t25]

Hi again,
while continuing following and learning , under Section modules

when you run script "./eval.bash" it shows

{ pkgs ? import <nixpkgs> { } }:
  ^
 error: cannot convert a function to JSON

can we convert function to json in nix? ( did i miss something )
so i just declared pkgs inside "let .... in" block

let
  pkgs = import <nixpkgs> {};
....
in

after executing it shows

while evaluating attribute 'name'
error: cannot convert a function application to JSON

after reading wiki , i followed with --strict

nix-shell -p jq --run "nix-instantiate --eval --json --strict | jq"

now it does show the expected output.

{
  "name": "Boaty McBoatface"
}

Please check on your end , i did double check about the error and also there might be better solution than this

[djacu]

@proofconstruction @fricklerhandwerk Other than my nit I think this is good. I can't think of another way to make the default.nix file work without using --apply and that adds a lot of complexity to the shell script.

[fricklerhandwerk]

Oh damn, nix-instantiate doesn't do autocall like nix-build and nix-shell.

[fricklerhandwerk]

This sucks. But we don't have to change the default argument, because that's still useful if you end up building derivations. Just the command line invocation becomes cumbersome and introduces redundancy:

nix-shell -p jq --run "nix-instantiate --eval --json --strict --arg pkgs 'import <nixpkgs> {}' | jq"