learnlisted

# /learn Delegate to `learning-curator`. ## Triggers (any one makes the task "notable") - Investigation took > 30 min - > 2 fix attempts before success - Surprised by behaviour - Found a non-obvious gotcha - Made a non-trivial trade-off - Bootstrapped something new (test framework, CI, infrastructure) ## Process 1. Read the last commit + PR description + investigation file (if exists). 2. Extract: - What we expected - What actually happened - Why - What we'd do differently 3. Tag with relevant types. 4. **Resolve the canonical learnings path.** `docs/learnings/` is gitignored (forge-dogfood publish-hygiene rule), so its single source of truth is the **main checkout's** `docs/learnings/` tree — *not* the working directory. `/pickup-task` hydrates worktrees by `cp -r` from the main checkout (`skills/pickup-task/SKILL.md` lines 47–53), and `/learn` must mirror that contract on the write side. See `spec/SPEC.md §Learnings store` for the canonical-store rule and why. Resolve the main checkout's absolute path via `git rev-parse --git-common-dir` (which always resolves to the main checkout's `.git` from anywhere — main or worktree). Compare against `pwd -P` so symlinked paths (e.g. macOS `/var` ↔ `/private/var`) don't trigger a spurious double-write: ```bash GIT_COMMON_DIR="$(git rev-parse --git-common-dir)" MAIN_ROOT="$(cd "$(dirname "${GIT_COMMON_DIR}")" && pwd -P)" PWD_REAL="$(pwd -P)" QUARTER="2026-Q2" # or curren