yamadashy/repomix · error · RepomixError

Failed to generate XML output: ${error instanceof Error ? er

Error message

Failed to generate XML output: ${error instanceof Error ? error.message : 'Unknown error'}

What it means

XML generation via the fast-xml-parser builder failed while serializing the prepared xmlDocument. Repomix wraps the builder's exception in a RepomixError with the original message preserved as the cause.

Source

Thrown at src/core/output/outputGenerate.ts:168

            git_diff_staged: renderContext.gitDiffStaged,
          }
        : undefined,
      git_logs: renderContext.gitLogEnabled
        ? {
            git_log_commit: renderContext.gitLogCommits?.map((commit) => ({
              date: commit.date,
              message: commit.message,
              files: commit.files.map((file) => ({ '#text': file })),
            })),
          }
        : undefined,
      instruction: renderContext.instruction ? renderContext.instruction : undefined,
    },
  };
  try {
    return xmlBuilder.build(xmlDocument);
  } catch (error) {
    throw new RepomixError(
      `Failed to generate XML output: ${error instanceof Error ? error.message : 'Unknown error'}`,
      error instanceof Error ? { cause: error } : undefined,
    );
  }
};

const generateParsableJsonOutput = async (renderContext: RenderContext): Promise<string> => {
  const jsonDocument = {
    ...(renderContext.fileSummaryEnabled && {
      fileSummary: {
        generationHeader: renderContext.generationHeader,
        purpose: renderContext.summaryPurpose,
        fileFormat: generateSummaryFileFormatJson(),
        usageGuidelines: renderContext.summaryUsageGuidelines,
        notes: renderContext.summaryNotes,
      },
    }),
    ...(renderContext.headerText && {

View on GitHub (pinned to f465ad9093)

Solutions

1. Read `error.cause` for the exact builder message.
2. Exclude problematic files with --ignore patterns (binary/control-character files).
3. Upgrade repomix — builder-level serialization bugs are often fixed upstream.
4. Validate that file contents passed to the renderer are strings with valid XML characters.

Example fix

// before
repomix --style xml  # fails on files with control chars
// after
repomix --style xml --ignore "**/*.bin,**/*.dat"

const hasBadXmlChars = (s: string) => /[\u0000-\u0008\u000B\u000C\u000E-\u001F]/.test(s);
// pre-scan packed files before generating:
if (files.some(f => hasBadXmlChars(f.content))) console.warn('Files contain control characters');

null

try {
  const xml = await generateOutput({ ...config, output: { ...config.output, style: 'xml' } }, ctx);
} catch (e) {
  if (e instanceof RepomixError && e.message.startsWith('Failed to generate XML output')) {
    console.error('XML build failed:', (e as { cause?: Error }).cause?.message);
  }
}

When it happens

Trigger: generateParsableXmlOutput(renderContext) calls xmlBuilder.build and the underlying builder throws — typically due to unencodable characters in file content/metadata, invalid XML attribute values (e.g. non-string scalar types), or a builder misconfiguration.

Common situations: Repositories containing binary or control-character-laden files whose content sneaks into XML attributes; unusual filenames with invalid XML characters; memory exhaustion on huge outputs.

Related errors

• Failed to generate JSON output: ${error instanceof Error ? e
• Unsupported output style for handlebars template: ${style}
• Output size exceeds JavaScript string limit. The repository
• Failed to compile template: ${error instanceof Error ? error
• Unsupported output style: ${config.output.style}

AI-assisted analysis of yamadashy/repomix@f465ad9093 (2026-08-29). Data as JSON: /api/errors/e10b0f9939b7166a. Report an issue: GitHub.