# Error Log > Captures non-obvious errors and their solutions as structured Obsidian notes for future reference. Use when: (1) /error-log command to capture an error from the current session, (2) /error-log to log a specific error, (3) user wants to document a tricky bug fix or error resolution. - Skill: `abhattacherjee/error-log` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add abhattacherjee/error-log` - Raw SKILL.md: https://api.skillmd.com/api/skills/abhattacherjee/error-log/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: abhattacherjee (https://skillmd.com/u/abhattacherjee) - Updated: 2026-09-10 - Page: https://skillmd.com/skills/abhattacherjee/error-log --- # Error Log — Capture Error Solutions to Obsidian Analyze the current conversation for error -> investigation -> fix patterns, structure them as reusable troubleshooting notes, and save to the Obsidian vault. **Tools needed:** Bash, Write, Read ## Procedure Follow these steps exactly. Do not skip steps or reorder them. ### Step 1 — Read config Run: ```bash cd "$(git rev-parse --show-toplevel 2>/dev/null || pwd)" python3 -c ' import sys, os import glob; sys.path.insert(0, max(glob.glob(os.path.expanduser("~/.claude/plugins/cache/*/obsidian-brain/*/hooks")), default="hooks")) from obsidian_utils import load_config c = load_config() if not c.get("vault_path"): print("ERROR: vault_path not configured", file=sys.stderr) sys.exit(1) print("VAULT=" + c["vault_path"]) print("SESS=" + c.get("sessions_folder", "claude-sessions")) print("INS=" + c.get("insights_folder", "claude-insights")) ' ``` Parse each output line as KEY=VALUE, splitting on the first `=`. If the file does not exist or is invalid JSON, tell the user: > Config not found. Please run `/obsidian-setup` first to configure your Obsidian vault. Stop here if config is missing. ### Step 2 — Validate vault access Run: ```bash test -d "$VAULT_PATH/$INSIGHTS_FOLDER" && test -w "$VAULT_PATH/$INSIGHTS_FOLDER" && echo "OK" || echo "FAIL" ``` If FAIL, tell the user: > The insights folder `$VAULT_PATH/$INSIGHTS_FOLDER` does not exist or is not writable. Run `/obsidian-setup` to fix this. Stop here if FAIL. ### Step 3 — Identify the error Check if the user provided an argument after `/error-log`. - **With argument** (e.g. `/error-log BrokenPipeError in subprocess`): Use the description to search the current conversation for matching error context, investigation steps, and resolution. - **Without argument** (bare `/error-log`): Scan the full conversation for error -> investigation -> fix patterns. Look for: - Stack traces, error messages, or exception output - Debugging steps taken (hypothesis, investigation, failed attempts) - The fix that ultimately resolved the issue - If multiple errors were resolved, present a numbered list and ask the user which to log If no error pattern is found in the conversation, tell the user: > No error -> fix pattern detected in this session. You can run `/error-log ` to manually describe an error to document. Stop here if no error is found. ### Step 4 — Structure the error note Draft the note body with these four sections. Each section should be concise but complete enough to be useful months later when encountering the same error: - **Error:** The exact error message, symptoms, and context where it appeared (include relevant stack trace snippets or command output if available, formatted as code blocks) - **Root Cause:** Why the error happened — the underlying reason, not just the surface symptom - **Fix:** The specific change or command that resolved it — include code diffs, config changes, or commands as code blocks - **Prevention:** How to avoid this error in the future — linting rules, config patterns, pre-checks, or design principles ### Step 5 — Auto-generate topic tags Based on the error content, generate 1-3 topic tags. Tags should be lowercase, hyphenated, and specific to the technology or domain. Examples: - `claude/topic/subprocess-pipes` - `claude/topic/python-async` - `claude/topic/npm-dependencies` - `claude/topic/git-hooks` ### Step 6 — Show preview and ask for edits Present the full note to the user including frontmatter: ``` --- type: claude-error-fix date: YYYY-MM-DD created_at: source_session: source_session_note: "[[]]" project: tags: - claude/error-fix - claude/project/ - claude/topic/ - claude/topic/ --- # ## Error ## Root Cause ## Fix ## Prevention ``` Where: - `YYYY-MM-DD` is today's date - `` is the current UTC timestamp at second precision. Get it via: ```bash python3 -c 'from datetime import datetime, timezone; print(datetime.now(timezone.utc).isoformat(timespec="seconds"))' ``` Example: `2026-04-24T18:42:11+00:00` - `` and `` are derived together. Get session context via the shared helper: ```bash cd "$(git rev-parse --show-toplevel 2>/dev/null || pwd)" python3 -c ' import sys, os import glob; sys.path.insert(0, max(glob.glob(os.path.expanduser("~/.claude/plugins/cache/*/obsidian-brain/*/hooks")), default="hooks")) from obsidian_utils import load_config, get_session_context c = load_config() ctx = get_session_context(c["vault_path"], c.get("sessions_folder", "claude-sessions")) print("SID=" + ctx["session_id"] + " HASH=" + ctx["hash"] + " PROJECT=" + ctx["project"] + " SESSION_NOTE=" + ctx["session_note_name"]) ' ``` Parse the output to get `SESSION_ID`, `HASH`, `PROJECT`, and `SESSION_NOTE`. **Important:** If `SESSION_ID` is `unknown`, use `unknown` for `source_session` and omit `source_session_note` entirely. - `` is the `PROJECT` value from `get_session_context()` (lowercased, hyphenated basename of cwd) - `` is a short, descriptive title for the error (e.g. "BrokenPipeError when piping subprocess output to head") - The `source_session_note` field creates an Obsidian backlink to the source session note Ask the user: > Preview above. Would you like to: > - **save** as-is > - **edit tags** — add or remove tags > - **edit content** — tell me what to change > - **cancel** — discard this note Wait for the user's response. Apply any requested edits and show the updated preview. Repeat until the user says **save** or **cancel**. If cancel, stop here. ### Step 7 — Generate filename Construct the filename from these parts: 1. **Date:** `YYYY-MM-DD` (today) 2. **Slug:** The error title, lowercased, spaces replaced with hyphens, non-alphanumeric characters (except hyphens) removed, truncated to 50 characters 3. **Hash:** 4-character hex hash derived from the current timestamp: `date +%s | md5 | cut -c29-32` (macOS) or `date +%s | md5sum | cut -c1-4` (Linux). Do NOT use `tail -c 4` — it counts the trailing newline as a byte and returns only 3 visible characters. 4. **Suffix:** `-error` Final filename: `YYYY-MM-DD---error.md` Example: `2026-04-04-brokenpipeerror-subprocess-pipe-a3f2-error.md` ### Step 8 — Write the note Run: ```bash mkdir -p "$VAULT_PATH/$INSIGHTS_FOLDER" ``` Then use the **Write** tool to write the full note (frontmatter + body) to: ``` $VAULT_PATH/$INSIGHTS_FOLDER/YYYY-MM-DD---error.md ``` Then set permissions: ```bash chmod 644 "$VAULT_PATH/$INSIGHTS_FOLDER/YYYY-MM-DD---error.md" ``` ### Step 9 — Confirm Print: > **Error fix logged!** > - File: `$VAULT_PATH/$INSIGHTS_FOLDER/` > - Tags: `claude/error-fix`, `claude/project/`, `claude/topic/`, ... > - Open in Obsidian to view. This note will appear in the "Error Fixes" section of the Project Index dashboard.