use temp dir for doctor.sh curl | bash instead of persisting clone

Shallow-clone into a temp directory with trap-based cleanup so doctor
remains truly side-effect-free. Reuses ~/Work/setup when it already exists.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

doctor.sh

@@ -25,37 +25,25 @@ set -uo pipefail
 if [ -n "${BASH_SOURCE[0]:-}" ] && [ -f "${BASH_SOURCE[0]}" ]; then
   SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 else
-  # Running via curl | bash — clone (or update) the repo at ~/Work/setup
-  SETUP_CLONE_DIR="$HOME/Work/setup"
+  # Running via curl | bash — need the repo for lib/ scripts.
+  # Use the existing local clone if available, otherwise shallow-clone
+  # into a temp directory and clean it up on exit.
   SETUP_REPO="${SETUP_REPO:-trusted/setup}"
   SETUP_REF="${SETUP_REF:-main}"
+  DOCTOR_TMPDIR=""
 
-  if [ -d "$SETUP_CLONE_DIR/.git" ]; then
-    # Abort if there are uncommitted changes
-    if ! git -C "$SETUP_CLONE_DIR" diff --quiet HEAD 2>/dev/null; then
-      echo "ERROR: $SETUP_CLONE_DIR has uncommitted changes."
-      echo "Commit or stash them, then re-run doctor."
-      exit 1
-    fi
-
-    # Abort if on the wrong branch
-    local_branch="$(git -C "$SETUP_CLONE_DIR" branch --show-current)"
-    if [ "$local_branch" != "$SETUP_REF" ]; then
-      echo "ERROR: $SETUP_CLONE_DIR is on branch '$local_branch', expected '$SETUP_REF'."
-      echo "Switch to $SETUP_REF, then re-run doctor."
-      exit 1
-    fi
-
-    echo "Updating setup from github.com/$SETUP_REPO ($SETUP_REF)..."
-    git -C "$SETUP_CLONE_DIR" pull --ff-only --quiet
+  cleanup_tmp() { [ -n "$DOCTOR_TMPDIR" ] && rm -rf "$DOCTOR_TMPDIR"; }
+  trap cleanup_tmp EXIT
+
+  if [ -d "$HOME/Work/setup/.git" ]; then
+    SCRIPT_DIR="$HOME/Work/setup"
   else
-    echo "Cloning setup from github.com/$SETUP_REPO ($SETUP_REF)..."
-    mkdir -p "$HOME/Work"
-    git clone "https://github.com/$SETUP_REPO.git" "$SETUP_CLONE_DIR" --quiet
-    git -C "$SETUP_CLONE_DIR" checkout "$SETUP_REF" --quiet
+    DOCTOR_TMPDIR="$(mktemp -d)"
+    echo "Fetching setup from github.com/$SETUP_REPO ($SETUP_REF)..."
+    git clone --depth 1 --branch "$SETUP_REF" \
+      "https://github.com/$SETUP_REPO.git" "$DOCTOR_TMPDIR" --quiet
+    SCRIPT_DIR="$DOCTOR_TMPDIR"
   fi
-
-  SCRIPT_DIR="$SETUP_CLONE_DIR"
 fi
 
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