[Epic] Debugger Usability and Stability Problems

[ndoschek]

Summary:

Multiple issues currently impact the debugging experience in Theia (IDE).
This umbrella issue is intended to track, discuss, and coordinate ongoing investigation and improvement efforts. Individual sub-issues may exist or be created for specific root causes as identified.

Description:

1. Breakpoints appear as not bound, although they are (see Breakpoints marked as not bound although they are #14882)
   Breakpoints are displayed as "not bound" even though they are actually hit during the debugging session.
   Breakpoint binding appears to be thread-dependent: when a breakpoint is hit in the frontend, other frontend breakpoints become visibly bound, and similarly for backend breakpoints. However, breakpoints are only shown as active when the main thread is selected, and since threads are collapsed by default, selecting a thread does not immediately update the breakpoint status.
   The sub-issue is already tracking this specific behavior and contains more observations.

2. Debug View steals focus, especially at startup
   When starting a backend and attempting to interact with the explorer or other parts of the IDE, the debug view or debug console repeatedly steals focus, making it nearly impossible to access other UI elements (like the Explorer view) on the host during startup. This focus issue appears to stabilize after the backend has finished starting, but is significantly disrupting.

3. Debug session restarts after pausing too long at a breakpoint
   If a user pauses at a breakpoint for an extended period of more than 60 seconds (e.g., to investigate variables), the debug session appears to reset: the output states "Waiting for the debugger to disconnect" and the program seems to be running again. Expanding the thread shows it is still paused at the previous location (as described in the breakpoint issue from item 1).
   If the user continues execution from here, the application restarts.

4. If startup of a launch config fails, the error notification indicates to Debug session initialization failed. See console for details.. However, the launch config gets removed from the debug console's launch config picker (select component) and hence the output cannot be viewed by the user. Even when a launch is not running anymore, we should keep the recently started launch configs in the select component to be able to select it and view the output.

This umbrella issue is meant for discussion and tracking and more sub issues can be extracted of course anytime.

Additional Information

• Operating System: all
• Theia Version: most recent