Compatibility issue: GUI opened from packet handler leaves mouse grabbed under Cleanroom

[Potato986]

Your CleanroomMC Discord Username

Potato

Cleanroom Version

25+ 0.3.34-alpha

Java Version

Java 25

Graphics Card Vendor

Other (Please Specify)

Bug Report

Minecraft: 1.12.2
Cleanroom: 0.3.34-alpha
Modpack: Dimension Hopper The Fall 1.5.10
Problem mod: dimhoppertweaks-3.0.1+1.12.2.jar

Reproduction:

1. Start the pack with Cleanroom.
2. Enter a world.
3. Hold a Skill Token.
4. Sneak + right click.
5. TokenExchangeGui opens, but mouse cursor cannot move / stays grabbed.

Expected:
The GUI opens with normal cursor control.

Actual:
The GUI renders, but mouse input is stuck.

Important detail:
The mod's PacketOpenGui.handle directly calls Minecraft.displayGuiScreen(new TokenExchangeGui(...)) from the packet
handler.
Patching it to schedule the GUI open on the Minecraft client thread via Minecraft.addScheduledTask fixes the issue.

This does not reproduce under legacy Forge, but the packet handler is thread-unsafe according to Forge networking
guidance. Could Cleanroom/Fugue add a compatibility workaround for this mod, or should this remain a mod-side bug?

Mod List

Full mod list attached as github-mod-list.txt.

Minecraft: 1.12.2
Modpack: Dimension Hopper: The Fall 1.5.10
Launcher/runtime: Cleanroom 0.3.34-alpha
Affected mod: dimhoppertweaks-3.0.1+1.12.2.jar

github-mod-list.txt

Final Checklist

• I have searched the issues and haven't found a similar issue.
• I have read the readme and know that what is action build.
• I have installed Fugue and it didn't fix my issue.
• I have installed Scalar Legacy and it didn't fix my issue.
• I have switched my Forgelin and LibrarianLib to continuous versions(check readme for more detail).
• I am running a test build from Cleanroom Github Actions. (Or, if I've compiled it myself I plan to fix the issue)
• I did not use PCL/PCLCE or other unsupported launchers.
  我没有使用 PCL/PCLCE 等其他未被支持的启动器。