oraios/serena · error · FileNotFoundError

Memory {old_name} not found.

Error message

Memory {old_name} not found.

What it means

move_memory (rename) raises FileNotFoundError when the source memory file old_name does not exist. The move/rename cannot proceed because there is nothing to move; note write-access checks for both names run first.

Source

Thrown at src/serena/memories/memory_manager.py:337

        memory_file_path.unlink()
        return f"Memory {name} deleted."

    def move_memory(self, old_name: str, new_name: str, is_tool_context: bool) -> str:
        """
        Rename or move a memory file.
        Moving between global and project scope (e.g. "global/foo" -> "bar") is supported.
        """
        old_name = self._sanitize_name(old_name)
        new_name = self._sanitize_name(new_name)
        self._check_not_ignored(old_name)
        self._check_not_ignored(new_name)
        self._check_write_access(new_name, is_tool_context)

        old_path = self.get_memory_file_path(old_name)
        new_path = self.get_memory_file_path(new_name)

        if not old_path.exists():
            raise FileNotFoundError(f"Memory {old_name} not found.")
        if new_path.exists():
            raise FileExistsError(f"Memory {new_name} already exists.")

        new_path.parent.mkdir(parents=True, exist_ok=True)
        shutil.move(old_path, new_path)

        return f"Memory renamed from {old_name} to {new_name}."

    def rename_memory_and_propagate_references(self, old_name: str, new_name: str, is_tool_context: bool) -> tuple[str, int]:
        """
        Renames a memory and updates every ``mem:OLD_NAME`` reference across all memories.

        Memories whose content does not contain a reference to ``old_name`` are left
        untouched (no spurious mtime changes). Memories that do are rewritten via
        :meth:`save_memory`.

        :param old_name: the current memory name (the source of the rename)
        :param new_name: the target memory name

View on GitHub (pinned to 7fcbca7e62)

Solutions

1. Verify the source exists via list_memories (or get_memory_file_path(...).exists()) before renaming.
2. Use the exact current name including the 'global/' prefix for global memories.
3. If it was already renamed, use the current name as old_name or treat the operation as complete.
4. Recreate the source with save_memory if it was accidentally deleted and must be moved.

Example fix

// before
manager.move_memory("old_notes", "new_notes", is_tool_context=True)  # FileNotFoundError
// after
if manager.get_memory_file_path("old_notes").exists():
    manager.move_memory("old_notes", "new_notes", is_tool_context=True)

if not manager.get_memory_file_path(old_name).exists():
    raise KeyError(f"cannot rename: source {old_name!r} does not exist")

def can_move(manager, old: str, new: str) -> bool:
    return manager.get_memory_file_path(old).exists() and not manager.get_memory_file_path(new).exists()

try:
    manager.move_memory(old_name, new_name, is_tool_context)
except FileNotFoundError:
    log.warning("source %r gone; skipping rename", old_name)

When it happens

Trigger: Calling move_memory(old_name, new_name, is_tool_context) where old_name was never created, was deleted, or is misspelled; also when old_name refers to a memory in the wrong scope (project vs global/<name>).

Common situations: Renaming after the memory was already renamed (double rename); agents hallucinating the source memory name; renaming a global memory without the 'global/' prefix (it exists only under the global dir).

Related errors

• Memory named '{name}' not found
• Memory {new_name} already exists.
• Project '{project_name}' not found in Serena configuration;
• Memory '{name}' matches an ignored_memory_patterns pattern a
• Bare "{self.GLOBAL_TOPIC}" is not a valid memory name. Use "

AI-assisted analysis of oraios/serena@7fcbca7e62 (2026-08-29). Data as JSON: /api/errors/a62f3e6c445e403a. Report an issue: GitHub.