Debug the loop

Build, Test, Fix, and Repeat

Use exact symptoms and errors to help the coding agent repair what the first attempt missed.

You will know how to turn a failed launch, missing control, or confusing state into a focused debugging request.

Expect the first attempt to be imperfect

In the build-along, restarting the app produced an address-already-in-use error. After that was fixed, refreshing the browser revealed that the Connect button had disappeared. Neither problem meant the project had to be abandoned.

This is the normal rhythm of vibe coding: the generated change may solve one problem while revealing another. Your job is to test the real behavior and report the smallest useful fact back to the agent.

Paste the exact error

When the terminal prints an error, copy it into the agent conversation. Include the command you ran and what you expected to happen.

If the agent offers several fixes, ask it to explain the tradeoff. In the video, stopping the already-running process was preferable to leaving it behind and quietly starting another copy on a different address.

Terminal error prompt
I ran [command] and expected [expected result], but the terminal returned this error:

[paste the exact error]

Please diagnose the most likely cause in this project. Prefer a fix that cleans up the underlying problem instead of leaving old processes or state behind. Give me the exact next command, explain what it changes, and tell me how to verify the result.

Describe what disappeared or changed

Visual regressions may not produce a terminal error. If a button disappears or a flow becomes impractical, say exactly that in plain English.

The video does this when the refreshed app no longer offers a practical in-app way to connect. The request is simple: add the connection button back to the interface while keeping the new case-details feature.

Interface regression prompt
After the latest change and browser refresh, the Connect to Descrybe control is no longer available in the app. The interface instead tells me to perform the connection from the command line, which is not practical for this tool. Restore an in-app connection control without removing the search or case-details features. Then tell me how you checked for regressions and how I should retest the full flow.

Restart and refresh deliberately

  • Use Control-C to stop the current process before restarting it.
  • Use the terminal’s command history instead of retyping a long launch command.
  • Read the new terminal output before switching to the browser.
  • Refresh the browser after the updated app is running.
  • Retest connection, search, and case details—not only the newest control.

Ask questions early

Coding agents are useful not only for writing code but also for explaining the project they created. Ask when you do not understand a command, an error, or the next step.

Over time, you will recognize more patterns yourself. Until then, careful questions are part of the workflow, not evidence that you are doing it wrong.