Agent skill

M06 Error Handling

by fjrevoredo in fjrevoredo/mini-diarium

CRITICAL: Use for error handling. An agent skill from fjrevoredo/mini-diarium.

MITAuto-check passedDevelopment

Install M06 Error Handling

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/m06-error-handling .claude/skills/m06-error-handling && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .claude/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/m06-error-handling .agents/skills/m06-error-handling && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .agents/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/m06-error-handling .cursor/skills/m06-error-handling && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .cursor/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/fjrevoredo/mini-diarium.git --path .agents/skills/m06-error-handling

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/m06-error-handling .gemini/skills/m06-error-handling && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .gemini/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/m06-error-handling .github/skills/m06-error-handling && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .github/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install fjrevoredo/mini-diarium m06-error-handling --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/m06-error-handling .opencode/skills/m06-error-handling && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "m06-error-handling" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m06-error-handling into .opencode/skills/m06-error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m06-error-handling", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: m06-error-handling
GitHub stars: 308
Used in: 1 other repo
Token cost: ~1.1k tokens
SKILL.md length: 342 words
Files: 3
Skills in repo: 41
Repo updated: Oct 7, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

CRITICAL: Use for error handling. An agent skill from fjrevoredo/mini-diarium.

Works in 3 steps: What kind of failure is this? → Who handles this? → What context is needed?
Tasks that involve Error handling
SKILL.md covers Core Question, Error → Design Question, Thinking Prompt and Trace Up ↑, plus 7 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

M06 Error Handling is an agent skill from fjrevoredo/mini-diarium. CRITICAL: Use for error handling. Triggers: Result, Option, Error, ?, unwrap, expect, panic, anyhow, thiserror, when to panic vs return Result, custom error, error propagation, 错误处理, Result 用法, 什么时候用 panic

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 4 other files (for example `examples/library-vs-app.md` and `patterns/error-patterns.md`).

It sits in Development, covering Error handling. The repository describes itself as: A local-only journal with serious encryption. Free, open source, and never touches the internet. The licence is MIT.

When your agent uses it

Tasks that involve Error handling

Example prompts

“/m06-error-handling”

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

What kind of failure is this?
Who handles this?
What context is needed?

What it can do on your machine

Read from SKILL.md and the folder at commit 3ddc537. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

M06 Error Handling loads about 1.1k tokens when it runs. Until then it costs about 56 tokens; SKILL.md has 342 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~56
When it runs · the whole SKILL.md, loaded when a task matches: ~1.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from fjrevoredo/mini-diarium at commit 3ddc537, republished under its MIT licence (© fjrevoredo). 342 words, ~1,117 tokens.

Download SKILL.mdSave it as .claude/skills/m06-error-handling/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.

name: m06-error-handling
description: CRITICAL: Use for error handling. Triggers: Result, Option, Error, ?, unwrap, expect, panic, anyhow, thiserror, when to panic vs return Result, custom error, error propagation, 错误处理, Result 用法, 什么时候用 panic
user-invocable: false

Error Handling

Layer 1: Language Mechanics

Core Question

Is this failure expected or a bug?

Before choosing error handling strategy:

Can this fail in normal operation?
Who should handle this failure?
What context does the caller need?

Error → Design Question

Pattern	Don't Just Say	Ask Instead
unwrap panics	"Use ?"	Is None/Err actually possible here?
Type mismatch on ?	"Use anyhow"	Are error types designed correctly?
Lost error context	"Add .context()"	What does the caller need to know?
Too many error variants	"Use Box`<dyn Error>`"	Is error granularity right?

Thinking Prompt

Before handling an error:

What kind of failure is this?
- Expected → Result<T, E>
- Absence normal → Option<T>
- Bug/invariant → panic!
- Unrecoverable → panic!
Who handles this?
- Caller → propagate with ?
- Current function → match/if-let
- User → friendly error message
- Programmer → panic with message
What context is needed?
- Type of error → thiserror variants
- Call chain → anyhow::Context
- Debug info → anyhow or tracing

Trace Up ↑

When error strategy is unclear:

"Should I return Result or Option?"
    ↑ Ask: Is absence/failure normal or exceptional?
    ↑ Check: m09-domain (what does domain say?)
    ↑ Check: domain-* (error handling requirements)

Situation	Trace To	Question
Too many unwraps	m09-domain	Is the data model right?
Error context design	m13-domain-error	What recovery is needed?
Library vs app errors	m11-ecosystem	Who are the consumers?

Trace Down ↓

From design to implementation:

"Expected failure, library code"
    ↓ Use: thiserror for typed errors

"Expected failure, application code"
    ↓ Use: anyhow for ergonomic errors

"Absence is normal (find, get, lookup)"
    ↓ Use: Option<T>

"Bug or invariant violation"
    ↓ Use: panic!, assert!, unreachable!

"Need to propagate with context"
    ↓ Use: .context("what was happening")

Quick Reference

Pattern	When	Example
`Result<T, E>`	Recoverable error	`fn read() -> Result<String, io::Error>`
`Option<T>`	Absence is normal	`fn find() -> Option<&Item>`
`?`	Propagate error	`let data = file.read()?;`
`unwrap()`	Dev/test only	`config.get("key").unwrap()`
`expect()`	Invariant holds	`env.get("HOME").expect("HOME set")`
`panic!`	Unrecoverable	`panic!("critical failure")`

Library vs Application

Context	Error Crate	Why
Library	`thiserror`	Typed errors for consumers
Application	`anyhow`	Ergonomic error handling
Mixed	Both	thiserror at boundaries, anyhow internally

Decision Flowchart

Is failure expected?
├─ Yes → Is absence the only "failure"?
│        ├─ Yes → Option<T>
│        └─ No → Result<T, E>
│                 ├─ Library → thiserror
│                 └─ Application → anyhow
└─ No → Is it a bug?
        ├─ Yes → panic!, assert!
        └─ No → Consider if really unrecoverable

Use ? → Need context?
├─ Yes → .context("message")
└─ No → Plain ?

Common Errors

Error	Cause	Fix
`unwrap()` panic	Unhandled None/Err	Use `?` or match
Type mismatch	Different error types	Use `anyhow` or `From`
Lost context	`?` without context	Add `.context()`
`cannot use ?`	Missing Result return	Return `Result<(), E>`

Anti-Patterns

Anti-Pattern	Why Bad	Better
`.unwrap()` everywhere	Panics in production	`.expect("reason")` or `?`
Ignore errors silently	Bugs hidden	Handle or propagate
`panic!` for expected errors	Bad UX, no recovery	Result
Box`<dyn Error>` everywhere	Lost type info	thiserror

When	See
Domain error strategy	m13-domain-error
Crate boundaries	m11-ecosystem
Type-safe errors	m05-type-driven
Mental models	m14-mental-model

Files

SKILL.md and 2 other files in .agents/skills/m06-error-handling of fjrevoredo/mini-diarium.

SKILL.md
examples/library-vs-app.md
patterns/error-patterns.md

Open the folder on GitHubat commit 3ddc537

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in fjrevoredo/mini-diarium, which our catalogue first saw on October 7, 2026.

NeverSight/learn-skills.devdata/skills-md/actionbook/rust-skills/m06-error-handling

Compare with similar skills

M06 Error Handling next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

M06 Error Handling compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
M06 Error Handling this skillfjrevoredo/mini-diarium	308	1 repos	~1.1k	Automated safety check: Pass	MIT	today
Mole Bug Patternstw93/Mole	70k	—	~2k	Automated safety check: Pass	GPL-3.0	today
Native Data FetchingCherryHQ/cherry-studio-app	4k	6 repos	~2.9k	Automated safety check: Notes	MIT	today
Rust Best Practicesfarm-fe/farm	5.6k	3 repos	~1.1k	Automated safety check: Pass	MIT	16 days ago
R Function Input Validationtidyverse/dplyr	5.1k	1 repos	~2.3k	Automated safety check: Pass	Custom licence	4 mo ago
Next Best Practicesvercel-labs/openreview	1.7k	18 repos	~1k	Automated safety check: Pass	None	7 mo ago

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Questions about M06 Error Handling

What does M06 Error Handling do?

CRITICAL: Use for error handling. An agent skill from fjrevoredo/mini-diarium. M06 Error Handling is an agent skill from fjrevoredo/mini-diarium. CRITICAL: Use for error handling.

When should I use M06 Error Handling?

M06 Error Handling fits situations like: tasks that involve Error handling.

How do I install M06 Error Handling in Claude Code?

Run `npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a claude-code`. Or copy the skill folder (.agents/skills/m06-error-handling in fjrevoredo/mini-diarium) into .claude/skills/m06-error-handling in your project. Claude Code loads it when a task matches its description.

How do I install M06 Error Handling in Codex?

Run `npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a codex`. Or copy the skill folder (.agents/skills/m06-error-handling in fjrevoredo/mini-diarium) into .agents/skills/m06-error-handling in your project. Codex loads it when a task matches its description.

Can I use M06 Error Handling in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add fjrevoredo/mini-diarium --skill m06-error-handling -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/m06-error-handling, .gemini/skills/m06-error-handling, .github/skills/m06-error-handling and .opencode/skills/m06-error-handling in your project.

What does M06 Error Handling need to run?

SKILL.md names no scripts, command-line tools or credentials: M06 Error Handling is instructions for the agent only.

Does M06 Error Handling access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is M06 Error Handling safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does M06 Error Handling use?

M06 Error Handling is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does M06 Error Handling use?

About 1.1k tokens (SKILL.md is roughly 4.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to M06 Error Handling?

Skills that share tags, products or a category with M06 Error Handling: Mole Bug Patterns (tw93/Mole, 70k stars), Native Data Fetching (CherryHQ/cherry-studio-app, 4k stars), Rust Best Practices (farm-fe/farm, 5.6k stars) and R Function Input Validation (tidyverse/dplyr, 5.1k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains M06 Error Handling?

fjrevoredo (a GitHub user) maintains it in fjrevoredo/mini-diarium, which has 308 GitHub stars. The repository holds 41 skills in this directory. The repository was last updated on October 7, 2026.

Source: fjrevoredo/mini-diarium on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install M06 Error Handling

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Error Handling

Core Question

Error → Design Question

Thinking Prompt

Trace Up ↑

Trace Down ↓

Quick Reference

Library vs Application

Decision Flowchart

Common Errors

Anti-Patterns

Related Skills

Files

Used in 1 other repository

Compare with similar skills

Similar skills

More from fjrevoredo/mini-diarium

Related

Questions about M06 Error Handling