4개의 녹색 CI 검사. 네 명 모두 장님입니다.

Quick take

A broken CI check is loud: the pipeline turns red, someone looks. A blind check is silent — and silence renders identically to success.

We found four in one repo, in one day. All green:

• A GitHub Actions lint job with timeout-minutes: 15 and --timeout=15m inside. The tool’s timeout can never fire — the job dies first, and GitHub writes cancelled with no reason. It blocked our deploys for a full day.
• A line-endings fix that never reached existing machines. .gitattributes applies at checkout: 1230 of 1455 files still had CRLF while git status said clean.
• A guard that flagged its own comment, because it scanned prose as configuration.
• A signup report that counted our own laptop as a “high purchase intent” lead.

Nothing rotted in the code. The ground moved underneath it: a runner, an old worktree, a comment, a generated domain.

The question that found all four: when did this check last say no? “Nothing is wrong” and “I cannot see anything” render identically on every dashboard — and only one of them is true.

The long version, with all four post-mortems: https://dev.to/heinrichneb/one-repo-one-day-4-ci-guards-that-were-green-and-blind-oge

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