HKUDS/nanobot · error · ValueError

Unknown old_text

Error message

Unknown old_text

What it means

Error "Unknown old_text" thrown in HKUDS/nanobot.

Source

Thrown at nanobot/agent/tools/filesystem.py:928

            "Shows closest-match diagnostics on failure."
        )

    @staticmethod
    def _strip_trailing_ws(text: str) -> str:
        """Strip trailing whitespace from each line."""
        return "\n".join(line.rstrip() for line in text.split("\n"))

    async def execute(
        self, path: str | None = None, old_text: str | None = None,
        new_text: str | None = None,
        replace_all: bool = False, occurrence: int | None = None,
        line_hint: int | None = None, expected_replacements: int | None = None, **kwargs: Any,
    ) -> str:
        try:
            if not path:
                raise ValueError("Unknown path")
            if old_text is None:
                raise ValueError("Unknown old_text")
            if new_text is None:
                raise ValueError("Unknown new_text")
            if occurrence is not None and occurrence < 1:
                return ToolResult.error("Error: occurrence must be >= 1.")
            if line_hint is not None and line_hint < 1:
                return ToolResult.error("Error: line_hint must be >= 1.")
            if expected_replacements is not None and expected_replacements < 1:
                return ToolResult.error("Error: expected_replacements must be >= 1.")

            fp = self._resolve_write(path)
            file_exists = fp.exists()
            if file_exists and old_text == new_text:
                return ToolResult.error("Error: new_text must be different from old_text.")

            # Create-file semantics: old_text='' + file doesn't exist → create
            if not file_exists:
                if old_text == "":
                    fp.parent.mkdir(parents=True, exist_ok=True)

View on GitHub (pinned to 42f37dc4c0)

When it happens

Trigger: Thrown at nanobot/agent/tools/filesystem.py:928 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of HKUDS/nanobot@42f37dc4c0 (2026-08-26). Data as JSON: /api/errors/1ec102fd0f0601d8. Report an issue: GitHub.