The --language option must be a single line without control

Error message

The --language option must be a single line without control or invisible formatting characters.

What it means

Error "The --language option must be a single line without control or invisible formatting characters." thrown in Fission-AI/OpenSpec.

Source

Thrown at src/core/init.ts:1035

      skillsInvocableCommandSkips,
      removedCommandCount,
      removedSkillCount,
    };
  }

  // ═══════════════════════════════════════════════════════════
  // CONFIG FILE
  // ═══════════════════════════════════════════════════════════

  private normalizeLanguage(language: string | undefined): string | undefined {
    if (language === undefined) return undefined;

    const normalized = language.trim();
    if (!normalized) {
      throw new Error('The --language option requires a non-empty value.');
    }
    if (/\p{Cc}|\p{Bidi_Control}|[\u200B\u2028\u2029\uFEFF]/u.test(normalized)) {
      throw new Error(
        'The --language option must be a single line without control or invisible formatting characters.'
      );
    }
    const serializedContext = `${formatLanguageContext(normalized)}\n`;
    if (Buffer.byteLength(serializedContext, 'utf8') > MAX_CONTEXT_SIZE) {
      throw new Error(
        `The --language option is too long for OpenSpec's ${MAX_CONTEXT_SIZE / 1024}KB project context limit.`
      );
    }
    return normalized;
  }

  private languageContext(): string | undefined {
    if (!this.language) return undefined;
    return formatLanguageContext(this.language);
  }

  private async assertLanguageCanBeApplied(

View on GitHub (pinned to 6926ccb18a)

When it happens

Trigger: Thrown at src/core/init.ts:1035 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Fission-AI/OpenSpec@6926ccb18a (2026-08-25). Data as JSON: /api/errors/7826e16554d87938. Report an issue: GitHub.