pd-plugins/Gem no longer works

[raboof]

Describe the bug

Since #230569 the puredata Gem plugin no longer works.

Steps To Reproduce

Shell.nix:

{ pkgs ? import <nixpkgs> {} }:

pkgs.mkShell {
  buildInputs = [
    (pkgs.puredata-with-plugins [ pkgs.gem pkgs.cyclone ])
  ];
}

Then: pd -lib Gem

Expected behavior

Successfully load the Gem plugin and

Additional context

Apparently pd became more picky about the directories in the -path. With the following change:

  postInstall = ''
    mv "$out/lib/pd/extra/Gem" "$out/"
    rm -rf $out/lib
  '';

... the Gem plugin can now be loaded (the warnings about NDI are just warnings), but using Gem now segfaults.

Notify maintainers

@carlthome