fix: remove unsafe pop of messages

src/goose/cli/session.py

@@ -2,7 +2,7 @@
 from pathlib import Path
 from typing import Any, Dict, List, Optional
 
-from exchange import Message, ToolResult, ToolUse, Text
+from exchange import Message, ToolResult, ToolUse, Text, FailedToGenerateMessageError
 from prompt_toolkit.shortcuts import confirm
 from rich import print
 from rich.console import RenderableType
@@ -156,10 +156,10 @@ def run(self) -> None:
                 self.reply()  # Process the user message.
             except KeyboardInterrupt:
                 self.interrupt_reply()
-            except Exception:
+            except FailedToGenerateMessageError:
+                # rewind to right before the last user message
+                self.exchange.rewind_to_last_user_message()
                 print(traceback.format_exc())
-                if self.exchange.messages:
-                    self.exchange.messages.pop()
                 print(
                     "\n[red]The error above was an exception we were not able to handle.\n\n[/]"
                     + "These errors are often related to connection or authentication\n"