${specName} MODIFIED failed for header "### Requirement: ${m

Error message

${specName} MODIFIED failed for header "### Requirement: ${mod.name}" - header mismatch in content

What it means

Error "${specName} MODIFIED failed for header "### Requirement: ${mod.name}" - header mismatch in content" thrown in Fission-AI/OpenSpec.

Source

Thrown at src/core/specs-apply.ts:459

      }
      continue;
    }
    nameToBlock.delete(key);
    removedApplied++;
  }

  // MODIFIED
  let modifiedApplied = 0;
  for (const mod of plan.modified) {
    const key = normalizeRequirementName(mod.name);
    const currentBlock = nameToBlock.get(key);
    if (!currentBlock) {
      throw new Error(`${specName} MODIFIED failed for header "### Requirement: ${mod.name}" - not found`);
    }
    // Replace block with provided raw (ensure header line matches key)
    const modHeaderMatch = mod.raw.split('\n')[0].match(/^###\s*Requirement:\s*(.+)\s*$/i);
    if (!modHeaderMatch || normalizeRequirementName(modHeaderMatch[1]) !== key) {
      throw new Error(
        `${specName} MODIFIED failed for header "### Requirement: ${mod.name}" - header mismatch in content`
      );
    }
    const missingScenarios = findMissingCurrentScenarios(currentBlock, mod);
    if (missingScenarios.length > 0) {
      throw new Error(
        `${specName} MODIFIED failed for header "### Requirement: ${mod.name}" - current spec contains scenario(s) not present in the modified block: ${missingScenarios.map(name => `"${name}"`).join(', ')}. Refresh the change spec before archiving to avoid dropping scenarios.`
      );
    }
    // Identical content means the modification was already synced to the
    // baseline (early-sync pattern) — count only real replacements, so a
    // fully synced change still takes the "already in sync" write skip
    // instead of churning normalization differences into the file.
    if (normalizeBlockRaw(currentBlock.raw) !== normalizeBlockRaw(mod.raw)) {
      modifiedApplied++;
    }
    nameToBlock.set(key, mod);
  }

View on GitHub (pinned to 6926ccb18a)

When it happens

Trigger: Thrown at src/core/specs-apply.ts:459 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/6bccdef4422d750a. Report an issue: GitHub.