`globals::entitySystem` never populated by `Hook_StartupServer` under FEX-Emu on ARM — same CS2 buildid was working hours earlier

[chaos666agent]

Summary

On an ARM64 cloud host (Ampere A1, Ubuntu 22.04.5 aarch64) running CS2 via FEX-Emu, CounterStrikeSharp loads cleanly and plugins register/initialize fine, but globals::entitySystem stays nullptr for the lifetime of the process. Every entity-touching API call from plugin event handlers throws:

CounterStrikeSharp.API.Core.NativeException: Entity system yet is not initialized
   at CounterStrikeSharp.API.Core.NativeAPI.GetConcreteEntityListPointer() in .../Generated/Natives/API.cs:line 983
   at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
   ...
   at RetakesPlugin.Utils.PlayerHelper.IsValid(CCSPlayerController player)
   at RetakesPlugin.Events.PlayerEventHandlers.OnPlayerSpawn(EventPlayerSpawn event, GameEventInfo info)

What proves this is the entity-system init bug, not a plugin bug

• Static plugin init works: [Retakes 3.0.4 - QueueManager] Queue manager initialized (Max: 9, T Ratio: 0.45) fires correctly on map start
• CSS native init works: CSSharp: Globals loaded / CSSharp: Initialized GameSystem / CSSharp: Hooks added all log on boot
• The exception only fires on player-event handlers that traverse the entity system
• Source location: src/mm_plugin.cpp Hook_StartupServer is the only place that sets globals::entitySystem via interfaces::pGameResourceServiceServer->GetGameEntitySystem(). Either the hook never fires or GetGameEntitySystem() returns nullptr.

Environment

• Host: Ampere A1 (4-OCPU aarch64 cloud VM), Ubuntu 22.04.5 LTS
• CPU: ARM Cortex-A78 (CPU implementer 0x41)
• CS2: buildid 23371447 (1.41.6.4/14164, public branch, last server-side update May 22 2026)
• Runner: FEXInterpreter binary dated May 22 2026
• Metamod: 2.0.0-dev+1401, built May 4 2026 from efeabcf
• CSS tested: stock v1.0.368 (md5 6d7386639b23c0945f0308de5db9e614) AND mrc4tt/CounterStrikeSharp v1.0.384 (md5 0ac7189b22ea49778305f76a94cd3b77) — both reproduce the same bug
• Plugins: RetakesPlugin 3.0.4 (B3none), RetakesAllocator 2.4.2 (yonilerner), NoFallZone 1.2 — all show LOADED in css_plugins list
• DOTNET env: DOTNET_EnableWriteXorExecute=0 set

Critical timing detail

The SAME binaries and SAME CS2 buildid were running cleanly approximately 20 hours before the bug appeared:

• May 23 02:01 UTC — [Retakes 3.0.4 - QueueManager] Queue manager initialized + Force added bot Jaques to active players + OnPlayerHurt event with entitySystem populated — fully working
• May 23 22:25 UTC — first Entity system yet is not initialized exception
• The only intervening action was systemctl restart cs2-2.service
• CS2 buildid was 23371447 both before and after the restart (verified from journal logs at both timestamps)

This rules out a CS2 binary update as the cause. Something in the boot path is intermittent, and the working state was apparently lucky.

Reproduction

1. CS2 dedicated server on aarch64 + FEX-Emu, public 1.41.6.4
2. CSS v1.0.368 with-runtime
3. RetakesPlugin 3.0.4 + RetakesAllocator 2.4.2 + any plugin that calls entity APIs
4. systemctl start cs2.service
5. bot_add via RCON
6. Journal floods with Entity system yet is not initialized from every event handler

What we tried that did NOT help

• CS2 downgrade to build 23241720 (1.41.6.1) via Steam beta pin — same errors
• Complete wipe of addons/counterstrikesharp/, fresh extraction from upstream zip — same errors
• Fork: mrc4tt/CounterStrikeSharp v1.0.384 (May 24 2026, contains "Hook_StartupServer against spurious second call" patch) — same errors
• changelevel via RCON to retrigger StartupServer — same errors
• Two sequential changelevel calls to different maps — same errors
• 3 fresh systemctl restart cs2.service cycles — deterministic 12-error count on each successful boot (one SEGV'd on shutdown)
• All DOTNET_* flags applied per ARM/FEX docs

Likely root cause

Metamod's SourceHook installs a hook on INetworkServerService::StartupServer via x86_64 trampolines. FEX-Emu's translation layer may not handle the trampoline insertion or the subsequent invocation reliably, causing the hook to silently fail to fire (or fire with a context where pGameResourceServiceServer is nullptr).

The cs2-signatures tracker shows CSS as ✅ on Linux because tests are on native x86_64. The bug is specific to the FEX-translated environment.

Asks

• Can globals::entitySystem be initialized from a later/different hook point (e.g., first OnFrame, or via InitGameSystem lazy lookup) to avoid relying on SourceHook trampolines?
• Could CSS add a log line on Hook_StartupServer entry and on interfaces::pGameResourceServiceServer resolution so we can confirm which step fails under FEX?
• Any known SourceHook configuration that's more FEX-friendly?

Happy to provide further logs, gdb stacks, or test patches.