Add notice for PyPy users (DIS-3295)

dissect/target/tools/shell.py

@@ -9,6 +9,7 @@
 import logging
 import os
 import pathlib
+import platform
 import pydoc
 import random
 import re
@@ -1442,6 +1443,18 @@ def main() -> None:
     if args.quiet:
         logging.getLogger("dissect").setLevel(level=logging.ERROR)
 
+    # PyPy readline is stuck in Python 2.7
+    if platform.python_implementation() == "PyPy":
+        print(
+            "\n".join(
+                [
+                    "Note for users of PyPy:",
+                    "Autocomplete might not work due to an outdated version of pyrepl/readline.py",
+                    "To fix this, please manually overwrite with latest dev-version from their source.",
+                ]
+            )
+        )
+
     try:
         open_shell(args.targets, args.python, args.registry)
     except TargetError as e: