name: debugging description: Debugging techniques and tools for IntelliJ development. Use when debugging IDE issues or investigating failures.

Debugging

Documentation

• Logger FAQ - Frequently asked questions about logging
• How to Investigate Freezes - Diagnosing IDE freezes
• Exception Analyzing FAQ - Analyzing and categorizing exceptions

Searching idea.log

When debugging IntelliJ code, search idea.log using these patterns:

Log Levels:

• FINE = debug level (from LOG.debug { })
• INFO = info level (from LOG.info())

Category Format: #<abbreviated.package.path>.<ClassName>

Example: com.intellij.openapi.wm.impl.status.IdeStatusBarImpl → #c.i.o.w.i.s.IdeStatusBarImpl

Search Examples:

# Debug logs from IdeStatusBarImpl
grep "FINE - #c.i.o.w.i.s.IdeStatusBarImpl" idea.log

# Info logs from IdeStatusBarImpl
grep "INFO - #c.i.o.w.i.s.IdeStatusBarImpl" idea.log

# All logs from a class
grep "#c.i.o.w.i.s.IdeStatusBarImpl" idea.log

End-to-End Behavior

When fixing issues where a user-facing entry point (script, command, API) doesn't behave as expected:

1. Trace the full execution chain from entry point to actual executor before making changes
2. Identify all layers that handle the relevant behavior - each layer may swallow, transform, or ignore it
3. Verify the fix at the entry point the user actually invokes, not just at the layer you modified
4. Add debugging output if still unsure - add to all layers to trace the issue