How can I debug runtime errors causing 'error command failed with exit code 1' during 'yarn start'?

If the error stems from a runtime error in your application's code, use debugging tools. Set breakpoints in your code using a debugger (e.g., the debugger built into VS Code or your IDE). Use `console.log()` statements extensively to track variable values and execution flow. Examine stack traces carefully to pinpoint the line of code where the error occurred. Consider using a logging library to capture more detailed information about the application's behavior during startup. Ensure you are using the correct Node.js version that is compatible with your application code.