debugging-tools

Debugging Tools

Debugging tools for stepping through code, inspecting state, and diagnosing runtime issues. This umbrella covers the two main ecosystems: Python and Node.js.

When to Use Debugger Tools

Tool	When
breakpoint() + pdb	Local, interactive, simplest. Add breakpoint() in source, run normally.
python -m pdb	Launch existing script under pdb with no source edits.
debugpy	Remote / headless / attach to already-running process. Talks DAP.
node inspect	Node.js built-in inspector. Zero install, CLI REPL.
ndb / CDP	Scriptable from Node/Python; automate many breakpoints across runs.

Start with breakpoint() or node inspect. These are the cheapest things that work.

Don't Use Debugger For

Things print() / console.log / pytest -vv --tb=long solve in under a minute. Breakpoint-driven debugging is heavier; use it when the payoff is real.

Quick Reference: pdb

Inside any pdb prompt ((Pdb)):

n(ext)     — Execute next line
s(tep)     — Step into function
c(ontinue) — Continue until breakpoint
l(ist)     — Show source around current line
p <expr>   — Print expression value
pp <expr>  — Pretty-print expression
b <line_no> — Set breakpoint at line

Quick Reference: node inspect

n            — Next
s            — Step into
o            — Step out
cont         — Continue
list(n)      — List source around line
repl         — Enter REPL mode to eval expressions
watch('var') — Watch expression across steps

Reference Files

• references/python-debugpy.md — Full pdb + debugpy reference (breakpoint(), remote attach, DAP)
• references/node-inspect-debugger.md — Full Node.js --inspect reference (CDP, breakpoints, heap snapshots)