oobabooga/textgen · error · RuntimeError

expecting newline or end at {remaining_src}

Error message

expecting newline or end at {remaining_src}

What it means

Error "expecting newline or end at {remaining_src}" thrown in oobabooga/textgen.

Source

Thrown at modules/grammar/grammar_utils.py:278

def parse_rule(state, src):
    name, remaining_src = parse_name(src)
    remaining_src = remove_leading_white_space(remaining_src, False)
    rule_id = get_symbol_id(state, name)

    if remaining_src[:3] != "::=":
        raise RuntimeError("expecting ::= at " + remaining_src)
    remaining_src = remove_leading_white_space(remaining_src[3:], True)

    remaining_src = parse_alternates(state, remaining_src, name, rule_id, False)

    if remaining_src and remaining_src[0] == "\r":
        remaining_src = remaining_src[2:] if remaining_src[1] == "\n" else remaining_src[1:]
    elif remaining_src and remaining_src[0] == "\n":
        remaining_src = remaining_src[1:]
    elif remaining_src:
        raise RuntimeError("expecting newline or end at " + remaining_src)
    return remove_leading_white_space(remaining_src, True)


def parse_ebnf(src):
    try:
        state = ParseState()
        grammar_repr = remove_leading_white_space(src, True)
        last_grammar_repr = ""
        while grammar_repr:
            if last_grammar_repr:
                last_parsed_rule_len = len(last_grammar_repr) - len(grammar_repr)
                logger.debug(f"last_parsed_rule: {last_grammar_repr[:last_parsed_rule_len]}")
            last_grammar_repr = grammar_repr
            grammar_repr = parse_rule(state, grammar_repr)
        state.grammar_encoding.append(0xFFFF)
        return state
    except RuntimeError as err:
        logger.warning("error parsing grammar:", err)

View on GitHub (pinned to ed888c71f2)

Solutions

1. End each grammar rule with a newline or the end of the input; remove any trailing characters after the rule body.
2. Check the grammar text near the reported position for a missing line break between rules.

When it happens

Trigger: Raised while parsing a GBNF grammar string: after a rule expression the parser found extra tokens where it expected a newline or the end of input. Triggers when a grammar rule line contains trailing characters (e.g. an unclosed alternation, stray literal, or missing newline between rules) in the grammar passed to the grammar-constrained generation feature.

Common situations: See trigger scenarios.

AI-assisted analysis of oobabooga/textgen@ed888c71f2 (2026-08-15). Data as JSON: /api/errors/9596e786c8f7106d. Report an issue: GitHub.