Diagnose ambiguous failures before editing. Use for unknown causes, intermittent behavior, performance regressions, or investigations needing evidence-ranked hypotheses.
Install
npx skills add JuliusBrussee/caveman --skill investigate-firstnpx skills add JuliusBrussee/caveman --skill investigate-first -a claude-code -gnpx skills add JuliusBrussee/caveman --skill investigate-first -a codex -ggemini skills install https://github.com/JuliusBrussee/caveman.git --path skills/investigate-firstgh skill install JuliusBrussee/caveman investigate-firstgit clone --depth 1 https://github.com/JuliusBrussee/caveman /tmp/JuliusBrussee__caveman
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/JuliusBrussee__caveman/skills/investigate-first ~/.claude/skills/investigate-first # Claude Code
cp -R /tmp/JuliusBrussee__caveman/skills/investigate-first ~/.agents/skills/investigate-first # Codex, Cursor, Gemini CLI, Copilot, OpenCode