diff --git a/deps/buildcore/scripts/pybb.py b/deps/buildcore/scripts/pybb.py
index 30716a5a..e7f18cae 100755
--- a/deps/buildcore/scripts/pybb.py
+++ b/deps/buildcore/scripts/pybb.py
@@ -52,7 +52,10 @@ def cmake_build(base_path: str, target: Optional[str]) -> int:
         # nothing to build
         return 0
     for d in os.listdir(base_path):
-        args = ['cmake', '--build', os.path.join(base_path, d)]
+        path = os.path.join(base_path, d)
+        if not os.path.isdir(path):
+            continue
+        args = ['cmake', '--build', path]
         if target is not None:
             args.extend(['--target', target])
         err = subprocess.run(args).returncode