Calf package does not set `LV2_PATH`

[smondet]

Issue description

Should a package like Calf, add its path to the LV2_PATH variable? (https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/audio/calf/default.nix)

Steps to reproduce

Run a nix-shell with -p ardour -p calf, start ardour5 → it doesn't find the calf plugins.

Add this before starting Ardour:

export LV2_PATH=$LV2_PATH:"$(dirname $(which calfjackhost))/../lib/lv2/"

and then it finds them.

Technical details

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

• system: "x86_64-linux"
• host os: Linux 4.14.65, NixOS, 18.03.133126.4df3426f5a5 (Impala)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 2.0.4
• channels(root): "nixos-18.03.133126.4df3426f5a5"
• channels(smondet): ""
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[jtojnar]

A setup hook for LV2 plugins would be nice. It would allow us to simplify pulseeffects expression

https://github.com/NixOS/nixpkgs/blob/c2c13157bb4339069874206fa9588e75d106c808/pkgs/applications/audio/pulseeffects/default.nix#L95

to

  --set LV2_PATH "$LV2_PATH"

[stale[bot]]

Thank you for your contributions.

This has been automatically marked as stale because it has had no activity for 180 days.

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[yurkobb]

I see that this path is not package-specific and in musnix it is configured in environment.variables:

    environment.variables = {
      DSSI_PATH   = "$HOME/.dssi:$HOME/.nix-profile/lib/dssi:/run/current-system/sw/lib/dssi";
      LADSPA_PATH = "$HOME/.ladspa:$HOME/.nix-profile/lib/ladspa:/run/current-system/sw/lib/ladspa";
      LV2_PATH    = "$HOME/.lv2:$HOME/.nix-profile/lib/lv2:/run/current-system/sw/lib/lv2";
      LXVST_PATH  = "$HOME/.lxvst:$HOME/.nix-profile/lib/lxvst:/run/current-system/sw/lib/lxvst";
      VST_PATH    = "$HOME/.vst:$HOME/.nix-profile/lib/vst:/run/current-system/sw/lib/vst";
    };

May this can be solved system-wide (and perhaps be the default for nixos)?

[stale[bot]]

I marked this as stale due to inactivity. → More info

[miniBill]

I would love to see this fixed

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/creating-a-standardized-audio-production-environment-with-flakes/22191/2

[SuperSandro2000]

Please create a nixosModule probably named programs.ardour setting those envs.