Steps to reproduce:

1. Open a project with no Library (cold) or enable Parallel workers in a project with a Library (warm)
2. Make sure you have URP and ShaderGraph installed
3. In {}Project Settings / Player / Shader Settings / Shader Precision Model{}, go from Platform Default and Unified (or vice versa). Let it re-import.
4. Select and re-import any asset
5. Repeat step 3-4 a few time

Actual results: No import worker crash

Expected results: Import workers crash

Reproducible with versions: 6000.2.0b3

Not reproducible with versions: 

Tested on (OS): Windows10, macOS, Ubuntu

Notes:

• This is the smallest repro we could find, but it's also occurring with other actions around ShaderGraph

 
{code:java}
========== OUTPUTTING STACK TRACE ==================
0x00007FFB3116208A (Unity) [C:\UnitySrc\unity_1\Runtime\Core\Containers\hash_set.h:1010] core::base_hash_set<core::pair<core::basic_string<char,core::StringStorageDefault<char> > const ,keywords::LocalKeyword,1>,core::hash_pair<core::hash<core::basic_string_ref<char> >,core::basic_string<char,core::StringStorageDefault<char> > >,core::equal_pair<std::equal_to<core::basic_string_ref<char> >,core::basic_string<char,core::StringStorageDefault<char> > > >::lookup<core::basic_string<char,core::StringStorageDefault<char> >,core::equal_pair<std::equal_to<core::basic_string_ref<char> >,core::basic_string<char,core::StringStorageDefault<char> > > > 
0x00007FFB3116FB7D (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\Keywords\LocalKeywordSpace.cpp:116] keywords::LocalSpace::Find 
0x00007FFB31170C94 (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\Keywords\KeywordRemap.cpp:20] keywords::KeywordRemap::Init 
0x00007FFB3120B522 (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\ShaderImpl\ShaderImpl.cpp:477] ShaderLab::IntShader::CreateKeywordRemap 
0x00007FFB3120F0EC (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\ShaderImpl\ShaderImpl.cpp:548] ShaderLab::IntShader::ResolveFallback 
0x00007FFB3101E751 (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\SerializedShader.cpp:1312] ShaderFromSerializedShaderMainThread 
0x00007FFB38175806 (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\Shader.cpp:1078] Shader::CreateFromParsedForm 
0x00007FFB38172A9D (Unity) [C:\UnitySrc\unity_1\Runtime\Shaders\Shader.cpp:1145] Shader::AwakeFromLoad 
0x00007FFB32180428 (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\AwakeFromLoadQueue.cpp:511] AwakeFromLoadQueue::InvokePersistentManagerAwake 
0x00007FFB32181B79 (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\AwakeFromLoadQueue.cpp:337] AwakeFromLoadQueue::PersistentManagerSingleQueueAwakeFromLoad 
0x00007FFB321815FD (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\AwakeFromLoadQueue.cpp:179] AwakeFromLoadQueue::PersistentManagerAwakeFromLoad 
0x00007FFB32077934 (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\PersistentManager.cpp:1369] PersistentManager::IntegrateAllThreadedObjects 
0x00007FFB320788F7 (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\PersistentManager.cpp:1543] PersistentManager::LoadAndIntegrateAllPreallocatedObjects 
0x00007FFB32079D67 (Unity) [C:\UnitySrc\unity_1\Runtime\Serialize\PersistentManager.cpp:2105] PersistentManager::LoadObjects 
0x00007FFB36EB0444 (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\LoadedAssetManagement\ReloadHelpers.cpp:374] ReloadInstances 
0x00007FFB36EAFCF1 (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\LoadedAssetManagement\ReloadHelpers.cpp:359] ReloadAssetIfLoaded 
0x00007FFB36BE171D (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\AssetImportWorkerClient.cpp:180] ReloadUpdatedAssets 
0x00007FFB36BA3B13 (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\AssetImportWorkerClient.cpp:538] <lambda_facd67bfaad784d1f33ac10a296f4325>::operator() 
0x00007FFB36E90FAF (Unity) [C:\UnitySrc\unity_1\External\asio\include\asio\detail\completion_handler.hpp:71] asio::detail::completion_handler<core::mutable_function<void __cdecl(void)>,asio::io_context::basic_executor_type<std::allocator<void>,0> >::do_complete 
0x00007FFB36E3DC44 (Unity) [C:\UnitySrc\unity_1\External\asio\include\asio\detail\impl\win_iocp_io_context.ipp:473] asio::detail::win_iocp_io_context::do_one 
0x00007FFB36E42264 (Unity) [C:\UnitySrc\unity_1\External\asio\include\asio\detail\impl\win_iocp_io_context.ipp:203] asio::detail::win_iocp_io_context::run 
0x00007FFB36E86269 (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\IOService\IOService.cpp:151] IOService::Run 
0x00007FFB36BE6B05 (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\AssetDatabaseInternal.cpp:5383] RunAssetImportWorkerClientV2 
0x00007FFB36BE6C4B (Unity) [C:\UnitySrc\unity_1\Modules\AssetDatabase\Editor\V2\AssetDatabaseInternal.cpp:5419] RunAssetImporterV2 
0x00007FFB34C5EEFF (Unity) [C:\UnitySrc\unity_1\Editor\Src\Application\Application.cpp:1524] Application::InitializeProject 
0x00007FFB36270C15 (Unity) [C:\UnitySrc\unity_1\Editor\Platform\Windows\WinEditorMain.cpp:1257] UnityMain 
0x00007FF624622F2A (Unity) [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288] __scrt_common_main_seh 
0x00007FFC0C717374 (KERNEL32) BaseThreadInitThunk
0x00007FFC0E6FCC91 (ntdll) RtlUserThreadStart
========== END OF STACKTRACE ===========
{code}