Silence PickleShare warnings when completing root modules.

A better way woudl be to try to use the shelves module ?

IPython/core/completerlib.py

@@ -117,7 +117,10 b' def get_root_modules():'
         # Don't try to scan for modules every time.
         return list(sys.builtin_module_names)
 
-    rootmodules_cache = ip.db.get('rootmodules_cache', {})
+    if getattr(ip.db, "_mock", False):
+        rootmodules_cache = {}
+    else:
+        rootmodules_cache = ip.db.get("rootmodules_cache", {})
     rootmodules = list(sys.builtin_module_names)
     start_time = time()
     store = False

IPython/core/interactiveshell.py

@@ -42,6 +42,8 b' try:'
 except ModuleNotFoundError:
 
     class PickleShareDB:  # type: ignore [no-redef]
+        _mock = True
+
         def __init__(self, path):
             pass