t4mer@notebook

// Problem Log

A public notebook of things that broke.

Not essays. Each entry is a problem, an environment, the failed attempts, the cause, the fix, and how much afternoon it consumed. Failed attempts are included on purpose.

Discovering that my Qt UI is QML rather than Widgets

Time wasted: 1 hour

I opened Qt Designer expecting to drag widgets. The screen did not appear as an editable form.

Qt 6.x · Qt Creator · QML project

Qt installation taking much longer than expected

Time wasted: 2 hours

The Qt online installer froze around 50% while downloading components, with a progress bar that had given up being honest.

Windows 11 · Qt 6.x · Visual Studio 2022

RabbitMQ redelivered a message I thought I had handled

Time wasted: 2 hours

A consumer performed a side effect (an HTTP call) and then crashed. The broker redelivered. The side effect happened twice.

RabbitMQ · PHP consumer

HTTP 421 Misdirected Request caused by an incorrect Host header

Time wasted: 2 hours

An outbound API call from Laravel returned 421 Misdirected Request. The same URL worked in Postman.

Laravel HTTP client / Guzzle · Nginx · HTTPS

Laravel authentication error returning HTML instead of JSON

Time wasted: An embarrassing amount of time

An unauthenticated or validation-failed API call returned an HTML login page or a Blade error, not JSON.

Laravel · API routes / middleware · HTTP client expecting JSON

API works in Postman but fails in Laravel

Time wasted: 2 hours

A provider endpoint returned 200 in Postman and 401 or 400 from Laravel with “the same” payload.

Laravel HTTP client / Guzzle · Postman · third-party REST API

Different PHP versions between CLI and the web server

Time wasted: 45 minutes

php -v and a phpinfo() page from the web server disagreed. A package existed in one and not the other.

Linux · PHP CLI · PHP-FPM

Nginx/PHP-FPM 502 that looked like Laravel

Time wasted: 90 minutes

Production returned 502 or a blank page. Staging was healthy. Laravel’s log file did not grow.

Ubuntu · Nginx · PHP-FPM · Laravel

Redis data appears stale

Time wasted: 2 hours

Periodic spikes in database load, or a UI showing a value that had already been updated. “We use Redis” was true and unhelpful.

Laravel · Redis · PHP-FPM · MySQL