Whetstone: 20 Claude Code skills, each written after one real failure

Whetstone showed up on Show HN as a set of 20 skills for Claude Code, licensed CC BY 4.0. Every entry traces back to a single concrete screwup: a check that passed against a stub instead of the real code path, a merge that quietly dropped a field, a green test that couldn't fail if it tried. Project and company details are scrubbed out of the write-ups, leaving only the mechanism.

The breakdown: 6 skills on verification and proof, 6 on planning and design, 4 on making changes safely, 3 on diagnosis and review, and 1 on writing skills themselves. Each lives in its own folder with a SKILL.md holding a one-paragraph rule, the anonymized incident, and a preflight checklist that fails loudly when an item goes unchecked.

Install it as a plugin with /plugin marketplace add iamakbarsha1/whetstone, or copy the folders into ~/.claude/skills/.