Terraria (105600)

Compatibility Report

• Name of the game with compatibility issues: Terraria
• Steam AppID of the game: 105600

System Information

• GPU: GTX 770
• Driver/LLVM version: NVIDIA 440.36
• Kernel version: 5.3.13-200.fc30
• Link to full system information report as Gist
• Proton version: 4.11-11

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Symptoms

The issue can be summed up in one Exception:

System.ArgumentException: Unable to sort because the IComparer.Compare() method returns inconsistent results. Either a value does not compare equal to itself, or one value repeatedly compared to another value yields different results. IComparer: 'System.Comparison``1[System.Int32]'.
  at System.Collections.Generic.IntrospectiveSortUtilities.ThrowOrIgnoreBadComparer (System.Object comparer) [0x0000b] in <d3b61d05e0d14bda9e0d978e561956eb>:0 
  at System.Collections.Generic.ArraySortHelper``1[T].Sort (T[] keys, System.Int32 index, System.Int32 length, System.Comparison``1[T] comparer) [0x0000f] in <d3b61d05e0d14bda9e0d978e561956eb>:0 
  at System.Collections.Generic.List``1[T].Sort (System.Comparison``1[T] comparison) [0x00018] in <d3b61d05e0d14bda9e0d978e561956eb>:0 
  at Terraria.UI.ItemSorting+ItemSortingLayers+<>c.<.cctor>b__40_108 (Terraria.UI.ItemSorting+ItemSortingLayer layer, Terraria.Item[] inv, System.Collections.Generic.List``1[T] itemsToSort) [0x00065] in <656615216c7c4289b27347cde9255acc>:0 
  at Terraria.UI.ItemSorting.SetupWhiteLists () [0x0021b] in <656615216c7c4289b27347cde9255acc>:0 
  at Terraria.Main.ClientInitialize () [0x001aa] in <656615216c7c4289b27347cde9255acc>:0 
  at Terraria.Main.Initialize () [0x0640a] in <656615216c7c4289b27347cde9255acc>:0 
  at Microsoft.Xna.Framework.Game.DoInitialize () [0x0000d] in <7ff45bf12adb4fa788baf2c3b3fc2840>:0 
  at Microsoft.Xna.Framework.Game.Run () [0x0000e] in <7ff45bf12adb4fa788baf2c3b3fc2840>:0 
  at Terraria.Program.LaunchGame (System.String[] args, System.Boolean monoArgs) [0x00092] in <656615216c7c4289b27347cde9255acc>:0

The latest Mono BCL breaks compatibility with older .NET versions, in the form of a more aggressive IComparer behavior. thfr found this when doing *BSD ports of various FNA games:

https://github.com/rfht/fnaify/issues/16

There's a patch in place for OpenBSD, and it's simple enough...

https://github.com/openbsd/ports/commit/7670058636c4985f47fa8da6dceaa9e7fec4f933

... but for accuracy this should only apply to games running against .NET 4.0 and older. Finding a way to determine this at runtime would be a more appropriate fix, and Mono upstream would be more likely to accept it.

Reproduction

1. Start Terraria
2. Read the Exception pop-up
3. Exit!

Start with the Terraria.UI.ItemSorting.SetupWhiteLists and Terraria.Main.ClientInitialize frames in the reported exception, then compare the linked OpenBSD ports patch and investigate Mono behavior for .NET 4.0 and older. Done means Terraria starts without the inconsistent-comparer exception while newer runtime behavior remains unaffected.