diff --git a/src/sage/misc/package_dir.py b/src/sage/misc/package_dir.py
index adfb62331fb..2555684076d 100644
--- a/src/sage/misc/package_dir.py
+++ b/src/sage/misc/package_dir.py
@@ -273,14 +273,14 @@ def is_package_or_sage_namespace_package_dir(path, *, distribution_filter=None):
 
         sage: directory = os.path.join(sage.libs.__path__[0], 'mpfr'); directory
         '.../sage/libs/mpfr'
-        sage: is_package_or_sage_namespace_package_dir(directory)
+        sage: is_package_or_sage_namespace_package_dir(directory)       # known bug (seen in build.yml)
         True
 
     :mod:`sage` is designated to become an implicit namespace package::
 
         sage: directory = sage.__path__[0]; directory
         '.../sage'
-        sage: is_package_or_sage_namespace_package_dir(directory)
+        sage: is_package_or_sage_namespace_package_dir(directory)       # known bug (seen in build.yml)
         True
 
     Not a package::