gh-139940: Handle RuntimeError when attaching to a non-existing process in pdb. (#139941)

Lib/pdb.py

@@ -3577,7 +3577,13 @@ def main():
             parser.error("argument -m: not allowed with argument --pid")
         try:
             attach(opts.pid, opts.commands)
-        except PermissionError as e:
+        except RuntimeError:
+            print(
+                f"Cannot attach to pid {opts.pid}, please make sure that the process exists "
+                "and is using the same Python version."
+            )
+            sys.exit(1)
+        except PermissionError:
             exit_with_permission_help_text()
         return
     elif opts.module: