Docker

Docker Build Works Locally and Fails in CI: The Eight Causes

Same Dockerfile, same repo, different result. The difference is nearly always cache, context, architecture, or something on your machine that is not in the image.

Shopify

Liquid Error: Nothing Renders and There Is No Error Message

Liquid fails quietly by design. Here is where the error actually goes and how to make your theme tell you what went wrong.

Node.js

EADDRINUSE: Finding and Killing Whatever Took Your Port

Address already in use. Here is how to find the process, why it sometimes is not a process at all, and why the port stays busy after you kill it.

JavaScript

Maximum Call Stack Size Exceeded When It Is Not Recursion

Sometimes it is infinite recursion. Often it is spreading a large array into a function call, and the fix is completely different.

AI

Running AI Agent Generated Code Safely: What Actually Contains It

If an agent can run shell commands, you have an arbitrary code execution problem. Here is what each isolation option genuinely protects against.

Shopify

Shopify Checkout Extensibility: What Broke and How to Migrate

checkout.liquid is gone. Here is what actually replaces each customisation and which ones have no replacement at all.

Networking

x509: certificate signed by unknown authority

Your browser trusts the certificate and your application does not. They use different trust stores, and inside a container there may not be one at all.

Debugging

Your Flaky Tests Are Not Flaky, They Are Telling You Something

A test that fails one time in fifty is reporting a real property of your system. Retrying it is throwing away the evidence.

React

Too Many Re-renders: Finding the Infinite Loop in React

React caught the loop and stopped it. Here are the five ways to create one and how the Profiler tells you which you have.

Docker

Debugging a Container With No Shell, No curl, and No ps

Distroless and scratch images are great for security and miserable when something breaks. Here is how to investigate a container that ships nothing.

DevOps

Your CI Cache Is Making Builds Slower and Occasionally Wrong

A cache with the wrong key restores nothing and uploads everything. A cache with too broad a key restores stale artifacts. Both are common.

JavaScript

Unexpected token < in JSON at position 0 Means You Got HTML

The angle bracket is the first character of an HTML error page. Your API returned a page, not JSON, and here is how to find out which page.