ciscoPacketTracer{7,8}: force xorg display mode

[buckley310]

Resolve: #190314

Force Packet Tracer to output in x11 mode. This helps some people using wayland desktops.

If a user on wayland has globally set QT_QPA_PLATFORM=wayland, packet tracer will crash, because it does not support wayland. This patch will allow Packet Tracer to still work for such users.

I have tested running Packet Tracer 7 and 8 on hyprland with QT_QPA_PLATFORM=wayland set.
Without this patch, it crashes. With this patch, it works.

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

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[gepbird]

Thanks for the fix, I made a VM with sway, reproduced the issue and confirmed this PR fixed it.

ciscoPacketTracer8 requires wayland as a build input, do you think it could work on Wayland natively? I'm still mainly on X11 and don't know much about Wayland, but I imagine it needs to be passed somewhere else too.

[gepbird]

After reading a little on the Arch wiki about this issue, I'm pretty sure we'd need to use nixpkgs built Qt libraries instead of the ones shipped with Packet Tracer if we want to run this natively on Wayland. I've tried it and I don't think it's worth it, because Qt 5 is no longer supported and packages like libsForQt5.qtwebengine is already marked as vulnerable with many CVEs.

Let's stick to your solution.

[buckley310]

Interesting. I wonder if packet tracer should be tagged with knownVulnerabilities

[gepbird]

Interesting. I wonder if packet tracer should be tagged with knownVulnerabilities

Yeah, that sounds the correct way of handling this inside nixpkgs. I don't think there are actual risk associated with those CVEs, because Packet Tracer is a simulation program, the virtual PCs with web browsers access content on the simulated network, etc.

[buckley310]

The only risky thing that comes to mind is the Cisco login stuff. That does at least some amount of network interaction.

[gepbird]

Sorry for going off-topic, I've opened a PR for that discussion.

There are no blockers for this PR.

[vcunat]

Why not, I guess.