Nginx C Module Debug

When your nginx module crashes in production and you're staring at a cryptic segfault, this is your systematic debugging guide. It covers 45 rules across core dump analysis, memory bug detection with AddressSanitizer and Valgrind, GDB workflow for inspecting request state, and tracing request flow through nginx's phase handlers and filter chains. The priority ranking helps you start with crash signatures and NULL pointer patterns before diving into dynamic tracing tools. It's built from nginx.org's official development docs and complements the nginx-c-modules skill by focusing purely on diagnosis rather than correct implementation. Most useful when you need to debug use-after-free bugs, pool corruption, or subrequest crashes that only happen under load.

skills.sh installs: 253
GitHub stars: 222
last updated: Aug 21, 2026

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Install

$ npx -y skills add pproenca/dot-skills --skill nginx-c-module-debug --agent claude-code

Installs into .claude/skills of the current project.

Files

nginx.org C Module Debugging Best Practices

Comprehensive debugging guide for nginx C modules, derived from the official nginx development documentation and production debugging experience. Contains 45 rules across 8 categories, prioritized by impact to guide systematic diagnosis of crashes, memory bugs, and behavioral issues in nginx modules.

Companion skills: This skill complements nginx-c-modules (correctness) and nginx-c-module-perf-reliability (performance). This skill covers debugging and diagnosis.