gatsbyjs/gatsby · error

${REPORTER_PREFIX} Error resolving Pages

Error message

${REPORTER_PREFIX} Error resolving Pages

What it means

In gatsby-plugin-sitemap's onPostBuild (gatsby-node.js:36-38), the plugin calls resolvePages(queryRecords) wrapped in Promise.resolve. If the user-provided (or default) resolvePages function throws synchronously or returns a rejected promise, the .catch handler calls reporter.panic. resolvePages is expected to return an array of page objects from the GraphQL query data.

Source

Thrown at packages/gatsby-plugin-sitemap/src/gatsby-node.js:37

    serialize,
  }
) => {
  const { data: queryRecords, errors } = await graphql(query)

  // resolvePages and resolveSiteUrl are allowed to be sync or async. The Promise.resolve handles each possibility
  const siteUrl = await Promise.resolve(resolveSiteUrl(queryRecords)).catch(
    err => reporter.panic(`${REPORTER_PREFIX} Error resolving Site URL`, err)
  )

  if (errors) {
    reporter.panic(
      `Error executing the GraphQL query inside gatsby-plugin-sitemap:\n`,
      errors
    )
  }

  const allPages = await Promise.resolve(resolvePages(queryRecords)).catch(
    err => reporter.panic(`${REPORTER_PREFIX} Error resolving Pages`, err)
  )

  if (!Array.isArray(allPages)) {
    reporter.panic(
      `${REPORTER_PREFIX} The \`resolvePages\` function did not return an array.`
    )
  }

  reporter.verbose(
    `${REPORTER_PREFIX} Filtering ${allPages.length} pages based on ${excludes.length} excludes`
  )

  const { filteredPages, messages } = pageFilter(
    {
      allPages,
      filterPages,
      excludes,
    },

View on GitHub (pinned to 8b06340921)

Solutions

1. Check the err in the panic output for the specific thrown error
2. If using a custom resolvePages, ensure it handles the query result shape returned by your query option
3. Add null/undefined guards inside resolvePages: if (!data?.allSitePage?.nodes) return []
4. Test resolvePages independently by logging the queryRecords shape

Example fix

// before: custom resolvePages accessing undefined
resolvePages: (data) => data.allSitePage.nodes.map(node => ({
  path: node.path,
  // if data.allSitePage is undefined, this throws
})),

// after: add guards
resolvePages: (data) => {
  if (!data?.allSitePage?.nodes) return []
  return data.allSitePage.nodes.map(node => ({
    path: node.path,
  }))
},

// Validate resolvePages output before passing to the plugin
const testData = { allSitePage: { nodes: [{ path: '/' }] } }
try {
  const result = resolvePages(testData)
  if (!Array.isArray(result)) {
    throw new Error('resolvePages must return an array')
  }
} catch (e) {
  console.error('resolvePages has a bug:', e.message)
}

function isValidPagesResult(result: unknown): result is Array<Record<string, unknown>> {
  return Array.isArray(result) && result.every(item =>
    typeof item === 'object' && item !== null
  )
}

// Make resolvePages defensive:
resolvePages: (data) => {
  try {
    return data?.allSitePage?.nodes ?? []
  } catch (err) {
    console.error('resolvePages failed:', err)
    return []
  }
}

When it happens

Trigger: A custom resolvePages function throws by accessing an undefined property (e.g. data.allSitePage.nodes when the query shape differs). The default resolvePages receives null/undefined queryRecords because the query returned no data. Logic error inside a custom resolvePages implementation.

Common situations: Custom resolvePages that doesn't match the actual GraphQL query output shape. Query returns empty data. Plugin options changed query but not resolvePages (or vice versa).

Related errors

• Invalid plugin options for "gatsby-plugin-sitemap":
• ${REPORTER_PREFIX} Error resolving Site URL
• Error executing the GraphQL query inside gatsby-plugin-sitem
• ${REPORTER_PREFIX} The `resolvePages` function did not retur
• ${REPORTER_PREFIX} Error serializing pages

AI-assisted analysis of gatsbyjs/gatsby@8b06340921 (2026-08-13). Data as JSON: /api/errors/4bdccabb7516ad52. Report an issue: GitHub.