FoundationAgents/MetaGPT · error · ValueError

Unsupported formatter: {formatter}

Error message

Unsupported formatter: {formatter}

What it means

Raised by metagpt.utils.highlight.highlight(): the output formatter argument only accepts 'terminal' (TerminalFormatter) or 'html' (HtmlFormatter); any other string raises ValueError after the lexer has already been selected.

Source

Thrown at metagpt/utils/highlight.py:22

from pygments.lexers import PythonLexer, SqlLexer


def highlight(code: str, language: str = "python", formatter: str = "terminal"):
    # 指定要高亮的语言
    if language.lower() == "python":
        lexer = PythonLexer()
    elif language.lower() == "sql":
        lexer = SqlLexer()
    else:
        raise ValueError(f"Unsupported language: {language}")

    # 指定输出格式
    if formatter.lower() == "terminal":
        formatter = TerminalFormatter()
    elif formatter.lower() == "html":
        formatter = HtmlFormatter()
    else:
        raise ValueError(f"Unsupported formatter: {formatter}")

    # 使用 Pygments 高亮代码片段
    return highlight_(code, lexer, formatter)

View on GitHub (pinned to 11cdf466d0)

Solutions

1. Use formatter='terminal' or formatter='html'.
2. For other formatters (256-color, IRC, images), construct the pygments formatter object yourself and call pygments.highlight directly.
3. Check formatter value against the two allowed strings before calling.

Example fix

# before
highlight(code, formatter='terminal256')  # ValueError

# after
from pygments.formatters import Terminal256Formatter
from pygments import highlight as hl
print(hl(code, PythonLexer(), Terminal256Formatter()))

SUPPORTED_FORMATTERS = {'terminal', 'html'}
if formatter.lower() not in SUPPORTED_FORMATTERS:
    formatter = 'terminal'

def is_supported_formatter(formatter: str) -> bool:
    return isinstance(formatter, str) and formatter.lower() in {'terminal', 'html'}

try:
    out = highlight(code, formatter=fmt)
except ValueError:
    out = highlight(code, formatter='terminal')

When it happens

Trigger: Calling highlight(code, language='python', formatter='ansi'), 'console', 'latex' or any value besides 'terminal'/'html' (case-insensitive).

Common situations: Call sites assuming pygments formatter names (e.g. 'terminal256', 'terminal16m') are accepted; copy-paste from pygments docs into code that uses this simplified wrapper.

Related errors

• Unsupported language: {language}
• Only support for python, markdown, but got {language}
• Only support for language: python, markdown, but got {langua
• The invoice format is not zip, pdf, png, or jpg
• Query cannot be empty or contain only whitespace.

AI-assisted analysis of FoundationAgents/MetaGPT@11cdf466d0 (2026-08-14). Data as JSON: /api/errors/6ada2a86031072b7. Report an issue: GitHub.