ciscoPacketTracer8: fix script modules

[gepbird]

Closes #291445

As the bug got introduced with a refactor that moved away from buildFHSEnv, the only fix I found is moving back to it.

This PR is mostly a revert of 2920b6f with additional refactors and the addition of wayland for newer versions of packet tracer.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 25.05 Release Notes (or backporting 24.11 and 25.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[gepbird]

cc @griffi-gh @cooparo @ob7 @NemoSomnium @Guccel @Anifyuli @doolphin @sjcp7 for being involved in #291445.

You can test this PR with this command, as usual you may need to download the packet tracer deb file and rename it to what you see in the error message:

NIXPKGS_EXPORT_ALLOW_UNFREE=1 nix run github:gepbird/nixpkgs/packet-tracer-fix-script-modules#ciscoPacketTracer8 --impure --extra-experimental-features nix-command --extra-experimental-features flakes

The "Required Script Modules do not appear to be running. Please reinstall Cisco Packet Tracer." and the "Unable to deserialize." message boxes should be gone, and you should be able to see the script modules loaded. IoT devices also seem to work.

[griffi-gh]

Minor complaint but the way the -unwrapped package is currently defined makes it kinda hard to override the source;
what if i do not want to use the stateful/non-reproducible prefetch-url?

the only thing i was able to come up with is

• copy the ciscoPacketTracer8 derivation into my repo
• call callPackage on it and override requireFile with fetchurl (hacky~)

ciscoPacketTracer8' = (callPackage ./ciscoPacketTracer8.nix {
  requireFile = _: fetchurl {
    url = "https://.../cisco/Packet_Tracer822_amd64_signed.deb";
    sha256 = "6cd2b8891df92d2cad8b6fdc47480fc089de085c4f3fe95eb80d5450a2a7f72d";
  };
});

[griffi-gh]

Another thing:
my cursor looks weird whenever i hover over the Packet tracer window

Actually the same weird cursor as i see in Steam.. huh

and under KDE Plasma (aka the Qt GUI), it runs under x11 instead of Wayland, even without any env vars

[gepbird]

Minor complaint but the way the -unwrapped package is currently defined makes it kinda hard to override the source; what if i do not want to use the stateful/non-reproducible prefetch-url?

the only thing i was able to come up with is

* copy the `ciscoPacketTracer8` derivation into my repo

* call `callPackage` on it and override `requireFile` with `fetchurl` (hacky~)

ciscoPacketTracer8' = (callPackage ./ciscoPacketTracer8.nix {
  requireFile = _: fetchurl {
    url = "https://.../cisco/Packet_Tracer822_amd64_signed.deb";
    sha256 = "6cd2b8891df92d2cad8b6fdc47480fc089de085c4f3fe95eb80d5450a2a7f72d";
  };
});

Thanks for feedback! I'm not sure what's the best way to allow overriding, wrapping unwrapped and fhs-env with a function that takes in src should do the job but its a bit ugly, what do you think? (I intentionally didn't format the file to make the diff easier to read, here is that: 2647141)

Edit: what about putting packetTracerSource ? null at the top (next to version ? "8.2.2)? Then later using the provided packetTracerSource as a src if not null, otherwise the already defined requireFile (a1ee67c).

[gepbird]

Another thing: my cursor looks weird whenever i hover over the Packet tracer window

Actually the same weird cursor as i see in Steam.. huh

and under KDE Plasma (aka the Qt GUI), it runs under x11 instead of Wayland, even without any env vars

That looks normal to me as I see that cursor everywhere on my own system. I haven't looked into cursor themes, but could be that packet tracer is trying to use some other cursor icon that is not in your cursor theme. Do you also experience it with PT on master?

[ob7]

tested this out. seems to work well. also seems to fix some issues with certain pka files causing PT to crash. ( haven't tested extensively, just surface level )

[gepbird]

I'm not sure why ofborg-eval is failing, maybe rebasing to master will help.

[gepbird]

Fixed the merge conflict caused by #342352

[griffi-gh]

(another common pattern for packages using FHSenv is moving -unwrapped into a separate package, should this be applied here? idk i don't have much experience with this)