Steps to reproduce:
1. Open the “user’s attached project”
2. Select “Tools/Shader Tests/Test Shader Keywords (6000 API)” through the Main Menu
3. Observe the crash

Reproducible with versions: 6000.0.64f1, 6000.3.1f1, 6000.4.0b1, 6000.5.0a3
Couldn’t test with versions: 2023.1.0a26, 2023.1.20f1 (due to compiler errors)

Reproducible on: macOS 15.7.2 (M1 Max), Windows 11 Pro (25H2)
Not reproducible on: no other environment tested

First few lines of StackTrace:
#0 0x00000101394d8c in keywords::LocalKeywordState::operator=(keywords::LocalKeywordState const&)
#1 0x00000102200868 in GetKeywordMask(Shader, PassIdentifier const&, ShaderType, keywords::LocalKeywordState&, ShaderCompilerPlatform)
#2 0x000001022005e8 in ShaderUtil::GetPassKeywords(Shader, PassIdentifier const&, ShaderType, ShaderCompilerPlatform)
#3 0x00000100c833b4 in ShaderUtil_CUSTOM_GetPassStageKeywords(void*, PassIdentifier const&, ShaderType)
#4 0x000003e62d0df8 in (wrapper managed-to-native) UnityEditor.ShaderUtil:GetPassStageKeywords_Injected (intptr,UnityEngine.Rendering.PassIdentifier&,UnityEditor.Rendering.ShaderType) [{0x13370e5d8} + 0x98] (0x3e62d0d60 0x3e62d0e9c) [0x332b8ea80 - Unity Child Domain]