netdata/netdata · error · ScannerError

could not found expected ':'

Error message

could not found expected ':'

What it means

Error "could not found expected ':'" thrown in netdata/netdata.

Source

Thrown at src/collectors/python.d.plugin/python_modules/pyyaml3/scanner.py:289

        for level in self.possible_simple_keys:
            key = self.possible_simple_keys[level]
            if min_token_number is None or key.token_number < min_token_number:
                min_token_number = key.token_number
        return min_token_number

    def stale_possible_simple_keys(self):
        # Remove entries that are no longer possible simple keys. According to
        # the YAML specification, simple keys
        # - should be limited to a single line,
        # - should be no longer than 1024 characters.
        # Disabling this procedure will allow simple keys of any length and
        # height (may cause problems if indentation is broken though).
        for level in list(self.possible_simple_keys):
            key = self.possible_simple_keys[level]
            if key.line != self.line  \
                    or self.index-key.index > 1024:
                if key.required:
                    raise ScannerError("while scanning a simple key", key.mark,
                            "could not found expected ':'", self.get_mark())
                del self.possible_simple_keys[level]

    def save_possible_simple_key(self):
        # The next token may start a simple key. We check if it's possible
        # and save its position. This function is called for
        #   ALIAS, ANCHOR, TAG, SCALAR(flow), '[', and '{'.

        # Check if a simple key is required at the current position.
        required = not self.flow_level and self.indent == self.column

        # A simple key is required only if it is the first token in the current
        # line. Therefore it is always allowed.
        assert self.allow_simple_key or not required

        # The next token might be a simple key. Let's save it's number and
        # position.
        if self.allow_simple_key:

View on GitHub (pinned to 4864de85e2)

Solutions

1. The YAML scanner expected a ':' while scanning a mapping key.
2. Fix the YAML syntax: ensure mapping keys are followed by ':'.

When it happens

Trigger: Thrown at src/collectors/python.d.plugin/python_modules/pyyaml3/scanner.py:289 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of netdata/netdata@4864de85e2 (2026-08-15). Data as JSON: /api/errors/08f89f5f6f8a2fd9. Report an issue: GitHub.