`apx` is not working on NixOS

[coxde]

Describe the bug

When I run apx on NixOS, the output shows Unsupported setup detected, set a default distro and package manager in the config file.

Steps To Reproduce

Steps to reproduce the behavior:

1. run apx in terminal.
2. output shows Unsupported setup detected, set a default distro and package manager in the config file.

Expected behavior

It should find the config.json file in $out/etc/apx/config.json and run as expected.

Additional context

I'm not very familiar with NixOS, but it seems that apx will look for config.json in /usr/share/apx/. But NixOS won't follow FHS, the config.json is located in $out/etc/apx/config.json. Related issue: Vanilla-OS/apx#238

Notify maintainers

Thank you! @dit7ya @fabaff

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

 - system: `"x86_64-linux"`
 - host os: `Linux 6.4.10, NixOS, 23.11 (Tapir), 23.11.20230816.caac0eb`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.17.0`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

[FliegendeWurst]

Fixed in #266262