CompareWithCurrentState() assertion fail

[sq2mo]

Hardware

• CPU: Intel(R) Core(TM) i5-3470
• RAM: 8G DIMM DDR3 Synchronous 1600 MHz
• GPU: built-in
• SDR: Local SDRPlay clone

Software

• Operating System: Ubuntu 22.04.4 LTS
• SDR++: v1.2.0 nightly built 15th July.

Bug Description SDR++ crashes, leaving the following message on terminal: [17/07/2024 17:27:23.000] [WARN] Demod switch took 12165 us [17/07/2024 17:27:23.000] [INFO] Rigctl command: 'AOS' [17/07/2024 17:27:28.000] [INFO] Rigctl command: 'LOS' sdrpp: /root/SDRPlusPlus/core/src/imgui/imgui.cpp:8121: void ImGuiStackSizes::CompareWithCurrentState(): Assertion `SizeOfItemFlagsStack >= g.ItemFlagsStack.Size && "PushItemFlag/PopItemFlag Mismatch!"' failed. Aborted (core dumped)

Steps To Reproduce

1. Launch SDR++.
2. Run for many hours, changing the frequency using rigctl server.
3. Sudden crash.

[AlexandreRouma]

It's a known thread safety issue