Debugging examines program execution and data to locate or understand faults. In highly concurrent and distributed BEAM systems, classical step-by-step debugging becomes difficult because processes, timeouts, and nodes cannot be coordinated into one meaningful sequence. section 13.3 section 13.3.1
Prefer strategies that preserve the system’s concurrent behavior:
- Use logging and tracing to collect enough context to identify the cause of a failure. section 13.3.1
- Start with Elixir’s Logger output: crashed OTP-compliant processes such as GenServers report an error and stack trace with file and line information. section 13.3.1
- Add IO.inspect when the stack trace lacks sufficient evidence; it prints an expression’s result and returns that result, preserving behavior. section 13.3.1
Inspecting a suspicious pipeline
Pipe an intermediate value through IO.inspect to observe it without changing the surrounding computation: value |> IO.inspect() |> next_step(). section 13.3.1
