Apply when debugging. Trace each symptom to its root cause and fix it there; reproduce first, ask why until you reach it, resist nil-check guards that silence crashes.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Fix Root Causes
When debugging, do not fix symptoms. Trace every problem to its root cause and fix it there.
**Why:** Symptom fixes accumulate. Each workaround makes the system harder to reason about, and the real bug remains. Root-cause fixes are slower upfront but reduce total debugging time.
**Pattern:**
- Reproduce first
- Ask "why" until you hit the root cause
- Do not add guards solely to silence symptoms; validate optional or externally supplied values at their boundary when absence is valid.
- If a workaround needs a paragraph-long comment to justify it, the code is wrong (fix the code, not the comment)
- Check for the pattern, not just the instance (grep for the same pattern, fix all instances)
- When stuck, instrument. Don't guess (add logging, read the actual error)
**Restart bugs: suspect state before code**
When something "fails after restart," suspect stale persistent state first: config files, caches, lock files, serialized state. If clearing a state file restores behavior, prioritize state validation as the fix.
The line at the top of this page pins the label git:20261006.f7c5841, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (1306 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag
Source
GitHub
iap/pstack-hermes · 32 stars · license a license file GitHub does not identify · pushed 2026-11-04 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_53qhjo5czcyvigzx
GET https://markdownregistry.com/api/v1/resolve?ref=iap/pstack-hermes/principle-fix-root-causes
GET https://markdownregistry.com/api/v1/blob/f6923b5a755b2a2f28418b1107abc137d7136a6582a8734c9aa80b539b1b791f
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
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