Crash with multiple stack traces when the Accelerator connection is lost during artifact upload

How to reproduce:

1. Unzip the attached “IN-149620“ project
2. In the project folder, open the terminal window and start the mock cache server with the command: “python repro/mock_accelerator.py --port 10999 --rst-after 2000000 --stall 3”
3. In the project folder, open a new terminal window and regenerate the asset contents of the project with this command: “python repro/generate_assets.py <project-path> --seed <any-new-number>” (make sure to change the placeholder variables)
4. In the project folder, open a new terminal window and run the Editor with this command: “<path to unity exe> -batchmode -projectPath <project-path> -enableCacheServer -cacheServerEndpoint 127.0.0.1:10999 -cacheServerNamespacePrefix repro3449941 -cacheServerEnableDownload false -cacheServerEnableUpload true -executeMethod ReproWait.Run -logFile repro-run.log” (make sure to change the placeholder variables)
5. Wait for ~5 minutes and open the generated “repro-run.log” file with a text editor
6. Observe the result at the end of the “repro-run.log” file

Actual result: Outputted logs show a crash
Expected result: Outputted logs show failed uploads and a reconnect attempt but the Editor does not crash

Reproducible with: 6000.0.0f1, 6000.0.80f1, 6000.3.21f1
Not reproducible with: 6000.5.0a7, 6000.5.6f1, 6000.6.0b6, 6000.7.0a3
Fixed in: 6000.6.0a1 (b0e692525f04)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes:

• The python scripts used in the reproduction are located in the “repro“ folder inside the project folder
• Reproduction requires Python 3.9 and above to be installed on the system
• In step 4, ReproWait keeps the Editor alive ~260 s and triggers a fresh upload wave every 25 s; each wave gives the mock another mid-upload disconnect

First few lines of the stack traces:
0x00007FFC5649AC40 (Unity) TcpProtobufSession::SendMessageAsync
0x00007FFC5649AFDF (Unity) TcpProtobufClient::SendMessageBatchedAsync
0x00007FFC563562C0 (Unity) AcceleratorClient::InternalGet
0x00007FFC563533D8 (Unity) <lambda_7e811f046b6344c0b6557af44dbdfa77>::operator()
0x00007FFC5647370E (Unity) asio::detail::completion_handler<core::mutable_function<void __cdecl(void)>,asio::io_context::basic_executor_type<std::allocator<void>,0> >::do_complete

0x00007FFC55F869DB (Unity) TcpProtobufClient::EndBatch
0x00007FFC55E4080F (Unity) <lambda_4943dcd2926113e32680dfec7ad01928>::operator()
0x00007FFC55F61E3E (Unity) asio::detail::completion_handler<core::mutable_function<void __cdecl(void)>,asio::io_context::basic_executor_type<std::allocator<void>,0> >::do_complete
0x00007FFC55F4F7FA (Unity) asio::detail::win_iocp_io_context::do_one
0x00007FFC55F50A44 (Unity) asio::detail::win_iocp_io_context::run