Debugging

1. Perform instrumentation with debug options

$ otel set -debug 
$ otel set -verbose

When using the -debug compilation option, the tool will compile an unoptimized binary while retaining all generated temporary files, such as debug logs and matched rules. You can review them to understand what kind of code the tool is injecting. The -verbose log will show you the detailed process of the tool.

2. Check .otel-build directory

Even without using the -debug option, the tool will retain the necessary modified file copies in .otel-build, and its structure is as follows:

.otel-build
├── debug.log
├── instrument # instrumented code, which is exactly the code we injected
│   ├── baggage
│   │   ├── otel_inst_file_context.go
│...
└── preprocess # temporary files generated during preprocess phase
    ├── backups # backup of original files in case of rollback
    ├── changed # changed files during preprocess phase
    ├── dry_run.log # dry run log
    └── matched_rules.json # matched rules