Selectively instruments code to capture runtime data for debugging failures and bugs. Use when investigating crashes, exceptions, unexpected behavior, test failures, or performance issues. Analyzes stack traces and error messages to identify suspicious code regions, then adds targeted logging, tracing, and assertions to capture variable values, execution paths, timing, and conditional branches. Supports Python, JavaScript/TypeScript, Java, and C/C++.
Selectively instruments code to capture runtime data for debugging failures and bugs. Use when investigating crashes, exceptions, unexpected behavior, test failures, or performance issues. Analyzes stack traces and error messages to identify suspicious code regions, then adds targeted logging, tracing, and assertions to capture variable values, execution paths, timing, and conditional branches. Supports Python, JavaScript/TypeScript, Java, and C/C++.
Failure-Oriented Instrumentation
Strategically instrument code to capture high-signal runtime data for debugging failures, focusing only on suspicious regions rather than comprehensive instrumentation.
Workflow
1. Analyze the Failure
Gather and analyze failure information:
Error message and exception type
Stack trace showing call chain
Failure location (file, line, function)
Reproduction steps or test case
Expected vs actual behavior
Identify suspicious code regions:
Functions in the stack trace
Code paths leading to the failure
Variables involved in the error
Conditional branches that may affect the outcome
2. Determine Instrumentation Strategy
Based on the failure type, choose instrumentation targets:
For crashes/exceptions:
Function entry/exit in stack trace
Variable values before the crash
Conditional branches leading to error path
Exception handling blocks
For incorrect results:
Variable values at key computation points
Conditional branch decisions
Loop iterations and state changes
Function return values
For performance issues:
Timing information for slow operations
Loop iteration counts
Resource allocation/deallocation
Function call frequency
For intermittent failures:
State variables that may cause non-determinism
Thread/concurrency information
External dependencies (I/O, network, time)
Retry logic and error recovery paths
3. Select Instrumentation Patterns
Choose appropriate patterns based on language and context. See language-specific references:
