Resolve PR and branch identity from GitHub as the authoritative source. Use this before any checkout, rebase, force-push, or when a plan references a branch by name.

The Problem This Solves

Branch names in plans, notes, and memory drift. The transcript showed a git checkout feat/s22-compute-config failing because the true head ref was feat/s22-compute-policy-config. That lookup took an extra round-trip to recover. This skill makes the lookup the first step, not a recovery.

Steps

1. Determine lookup direction from $ARGUMENTS:

   • If argument looks like a number → PR lookup
   • If argument looks like a branch name → branch lookup
   • If empty → show all open PRs with their head branches

2. PR → head branch:

   bash
   1gh pr view <N> --json number,title,headRefName,baseRefName,state \
   2  --jq '{pr: .number, title: .title, head: .headRefName, base: .baseRefName, state: .state}'

3. Branch → PR:

   bash
   1gh pr list --json number,title,headRefName,state \
   2  --jq '.[] | select(.headRefName == "<branch>") | {pr: .number, title: .title, state: .state}'

4. Check local branch existence:

   bash
   1git branch --list <branch>          # local
   2git ls-remote --heads origin <branch> | grep -q . && echo "exists remotely"

5. Fetch if missing locally but present remotely:

   bash
   1git fetch origin <branch>

6. Detect stacked PRs (base ≠ main):

   bash
   1gh pr list --json number,headRefName,baseRefName \
   2  --jq '.[] | select(.baseRefName != "main") | "PR #\(.number) \(.headRefName) → \(.baseRefName)"'

Output format

PR #1391 · feat/s22-compute-policy-config → main  [OPEN]
  local branch: present
  remote:       present
  stacked:      no

Guardrails

• Never proceed with a branch name that hasn't been confirmed against GitHub.
• When a local checkout fails with "pathspec did not match", immediately run this skill instead of trying other branch name guesses.
• Treat stacked PRs (base ≠ main) as requiring ordered integration.

ICN-specific notes

• Sprint plan docs (ops/state/sprint/current.json) store branch names that can drift between plan-time and execution-time. Always verify against gh pr view.
• Worktrees in icn-wt/ hold their own branch refs; a branch that appears absent may just be checked out in a worktree.