ci: add namespace package check

scripts/check-for-namespace-packages.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# TODO: Can we also check tests/? some folders in there require missing __init__.py
+ROOTS=("ddtrace")
+FAIL=0
+
+echo "Checking for accidental namespace packages..."
+
+for ROOT in "${ROOTS[@]}"; do
+    echo "Scanning '$ROOT'..."
+
+    # Only check roots that actually exist (CI safety)
+    if [[ ! -d "$ROOT" ]]; then
+        echo "  (skipped: directory does not exist)"
+        continue
+    fi
+
+    # Walk all directories under the root
+    while IFS= read -r dir; do
+        # Skip __pycache__
+        [[ "$dir" == *"__pycache__"* ]] && continue
+
+        # Directory contains Python or Cython files?
+        if compgen -G "$dir/*.py" >/dev/null || compgen -G "$dir/*.pyx" >/dev/null; then
+
+            # And it must contain __init__.py
+            if [[ ! -f "$dir/__init__.py" ]]; then
+                echo "❌ Missing __init__.py in: $dir"
+                FAIL=1
+            fi
+        fi
+
+    done < <(find "$ROOT" -type d)
+done
+
+if [[ "$FAIL" -eq 1 ]]; then
+    echo
+    echo "❌ ERROR: Missing __init__.py detected in source or test packages."
+    echo "   Please add empty __init__.py files to the directories listed above."
+    exit 1
+else
+    echo "✅ All Python package directories contain __init__.py"
+fi

scripts/gen_gitlab_config.py

@@ -271,6 +271,11 @@ def check(name: str, command: str, paths: t.Set[str]) -> None:
         command="scripts/check-dependency-bounds",
         paths={"pyproject.toml"},
     )
+    check(
+        name="Check for namespace packages",
+        command="scripts/check-for-namespace-packages.sh",
+        paths={"*"},
+    )
     if not checks:
         return