Book: LLM Observability Pocket Guide

Also by me: Thinking in Go (2-book series) — Complete Guide to Go Programming + Hexagonal Architecture in Go

My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools

Me: xgabriel.com | GitHub

Your agent runs the test suite. One test fails. Hundreds pass, and the runner tells the agent about every one of them: a header, progress for each file, the names of passing tests, a summary, and somewhere in there the stack trace it actually needs.

Test reporters were written for a person scrolling a terminal. A coding agent doesn't scroll. It reads what the command printed.

The useful part can get cut. A command that fails reaches Claude Code inline only up to roughly 10,000 characters . Past that, Claude gets "a head-and-tail excerpt of that size", with no file path to the rest. A red test run exits non-zero, so it counts as a failure, and it is the run where the middle matters most.

And whatever fits can stay.…