Bug Alert & Fix: STM32CubeMonitor wipes Variable List selection (.elf parsing issue) upon file renaming/switching

[k_nedelchev]

Hi everyone,

I wanted to share a frustrating issue I encountered in STM32CubeMonitor while working on a complex project (vienna_stm32g474), hoping to save some headaches for fellow developers.

The Problem:

When updating or switching to a new version of the .elf file in the Edit variables node / Edit exe-config node, the entire selected variable list (which contained around 30 complex nested structures) gets completely wiped out/deselected. Interestingly, this behavior occurred only in one specific node, while other lists on different flows updated perfectly fine, even though the variables still existed in the new file.

The Root Cause:

After a lot of debugging, we found out that STM32CubeMonitor handles the .elf file path/name as a strict unique hash key inside the flows.json architecture.
If you rename the file (e.g., creating a backup like project-Copy.elf) or switch paths manually in the UI dropdown, the internal parser treats it as an entirely new project schema. Instead of safely migrating the checkboxes, a silent exception occurs during the UI string-matching process of nested structs, and the internal JSON field "checked": true gets stripped off, completely resetting your selection to empty.

The Fix / Best Practice:

To prevent STM32CubeMonitor from ever wiping your variable lists again, follow these two rules:

1. Keep the filename and path 100% static: Never rename your output .elf file or manually switch files via the UI dropdown. Let STM32CubeIDE overwrite the exact same file in the Debug or Release folder upon compilation.
2. Automate the update on the background (The permanent fix): Instead of manually opening the config node and clicking "Update", use Node-RED's core automation:
   • Drag a watch node into your flow and point it to your absolute .elf file path.
   • Drag a link out node connected to the watch node.
   • In your other flows/tabs, place a link in node connected directly to the input pin of your variable list node.
   • Wire the links together.

Now, every time you hit Build in STM32CubeIDE, the watch node triggers a background re-parse across all flows simultaneously. The RAM addresses are updated on-the-fly, and your variable selections remain perfectly intact without any manual clicks.

Hope this helps anyone struggling with disappearing variables in CubeMonitor!

Tested on STM32CubeMonitor v1.12.0 and STM32CubeIDE v2.1.1).

Best regards,

k_nedelchev