Originally published on the Hubfly space blog .

TL;DR

What you get: a 3-step way to read any failed build, plus the exact fix for 5 common errors (wrong branch, wrong folder, bad base image, npm ci with no lockfile, and a deploy that fails after a good build).

Who it's for: anyone deploying from Git who just saw a red "Failed" badge and a wall of log text.

Time needed: about 10 minutes to read; each fix takes 1–2 minutes plus a rebuild of a few seconds.

You pushed your code, clicked deploy, and got a red Failed badge. The log is 60 lines long and the last line just says exit status 1 . That last line is almost never the answer. The real cause is usually one line, a little higher up, and once you know where to look you can fix most failed builds in a couple of minutes.

This guide shows you how to find that line and fix it. You'll learn which part of the build stopped, which line holds the cause, and the fix for five common errors.…