MultiMC instance lacks `legacy*` traits in the Minecraft component

[mineLdiver]

In the original generated json:

  "+traits": [
    "texturepacks",
    "FirstThreadOnMacOs"
  ],

This causes a crash with mods that interact with the crafting recipes sorter:

java.lang.ExceptionInInitializerError: null
	at net.minecraft.unmapped.C_95106612.m_49738346(C_95106612.java:103) ~[client-intermediary.jar:?]
	at net.minecraft.unmapped.C_95106612.m_06093942(C_95106612.java:82) ~[client-intermediary.jar:?]
	at net.minecraft.unmapped.C_81592558.<clinit>(C_81592558.java:223) ~[client-intermediary.jar:?]
	at net.minecraft.unmapped.C_19106855.<init>(C_19106855.java:14) ~[client-intermediary.jar:?]
	at net.minecraft.client.Minecraft.<init>(Minecraft.java:233) ~[client-intermediary.jar:?]
	at net.minecraft.unmapped.C_71402804.<init>(C_71402804.java:34) ~[client-intermediary.jar:?]
	at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:34) ~[minecraft-b1.7.3-client.jar:?]
	at net.fabricmc.loader.impl.game.minecraft.applet.AppletLauncher.init(AppletLauncher.java:138) ~[fabric-loader-0.18.4.jar:?]
	at net.fabricmc.loader.impl.game.minecraft.applet.AppletFrame.launch(AppletFrame.java:127) ~[fabric-loader-0.18.4.jar:?]
	at net.fabricmc.loader.impl.game.minecraft.applet.AppletMain.run(AppletMain.java:44) ~[fabric-loader-0.18.4.jar:?]
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:318) ~[?:?]
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773) ~[?:?]
	at java.awt.EventQueue$4.run(EventQueue.java:720) ~[?:?]
	at java.awt.EventQueue$4.run(EventQueue.java:714) ~[?:?]
	at java.security.AccessController.doPrivileged(AccessController.java:400) ~[?:?]
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87) ~[?:?]
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:742) ~[?:?]
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203) ~[?:?]
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124) ~[?:?]
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113) ~[?:?]
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109) ~[?:?]
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) ~[?:?]
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:90) ~[?:?]
Caused by: java.lang.IllegalArgumentException: Comparison method violates its general contract!
	at java.util.TimSort.mergeLo(TimSort.java:781) ~[?:?]
	at java.util.TimSort.mergeAt(TimSort.java:518) ~[?:?]
	at java.util.TimSort.mergeForceCollapse(TimSort.java:461) ~[?:?]
	at java.util.TimSort.sort(TimSort.java:254) ~[?:?]
	at java.util.Arrays.sort(Arrays.java:1308) ~[?:?]
	at java.util.ArrayList.sort(ArrayList.java:1804) ~[?:?]
	at java.util.Collections.sort(Collections.java:178) ~[?:?]
	at net.minecraft.unmapped.C_70737137.<init>(C_70737137.java:399) ~[client-intermediary.jar:?]
	at net.minecraft.unmapped.C_70737137.<clinit>(C_70737137.java:13) ~[client-intermediary.jar:?]
	... 23 more

Including the legacy* traits fixes the issue and allows the mods to run normally:

  "+traits": [
    "texturepacks",
    "FirstThreadOnMacOs",
    "legacyLaunch",
    "legacyServices"
  ],

[SpaceWalkerRS]

Thanks for the report. Just a few questions before I delve into this

• Is the Rust installer also affected by this issue?
• Are these traits relevant for only a subset of versions (e.g. 1.5.2 and below, or 1.12.2 and below)?

[DanyGames2014]

• Yes, the Rust Installer also omits these traits
• PrismLauncher applies legacyServices for r1.7.5 and below, this checks out with minecraft.wiki which lists this for the following r1.7.6 As a result of the old skin server being shut down, 1.7.6 is the oldest version of the game where skins still work without the use of modifications or third-party programs., legacyLaunch gets applied for r1.5.2 and below

[mineLdiver]

The crash is apparently unrelated to the lack of legacy traits. @DanyGames2014 noticed that adding those makes mods not load at all, hence I got the false impression that the crash was fixed. Adding noapplet trait makes the mods load again, but the crash also reappears.

Can't wrap my head around the crash. Babric Prism instance doesn't have the issue with the same mod (StationAPI) with the same Java runtime (Temurin 21), yet Ornithe does. Removing StationAPI's crafting recipe related mixins that cause the sorter to do extra work makes the game launch, but obviously hurts functionality. I don't see any other major differences between the two instances so I'm stuck.