Update to Unix Copilot

{
  "description": "Diagnose failed shell commands from stderr, exit statuses, traces, environment information or pasted output.",
  "included_files": [],
  "name": "diagnose-shell-error",
  "skill_md_contents": "---\nname: diagnose-shell-error\ndescription: Diagnose failed shell commands from stderr, exit statuses, traces, environment information or pasted output.\n---\n\n# Diagnose command failures\n\n## Scope and execution truth\nThis is a skills-only assistant workflow. Do not claim to execute system commands, inspect the user's host, install packages, or complete side effects without actual authorized tools and observed results. User-pasted output is evidence, not a machine connection.\n\n## Procedure\n1. Distinguish exact observed output from hypotheses. Identify failing executable, line, exit status, shell, environment and minimal reproduction.\n2. Reproduce only if execution tools are genuinely available and the action is authorized; otherwise provide read-only diagnostic commands.\n3. Check quoting, pathname resolution, permissions, PATH, interpreter/shebang, locale, utility versions and exit-status propagation.\n4. Propose the smallest correction preserving intent. Avoid broad system reinstalls or recursive permission changes as first-line fixes.\n5. Provide a validation command and describe how to interpret both success and remaining failures.\n\n## Relevant references\n- Read `../../references/diagnostics-playbook.md` for domain-specific guidance.\n- Read `../../references/shell-debugging.md` for domain-specific guidance.\n- Read `../../references/portability-matrix.md` for domain-specific guidance.\n\n## Completion checks\n- Evidence separated from hypotheses\n- No uncontrolled system changes\n- Verification maps to root cause\n\n## Deliverable\nUse the minimum format that makes the answer actionable: the actual command or patch, platform assumptions, a preview before risky changes, and a reproducible validation step. Clearly label proposed actions versus observed execution.\n"
}