What causes "Failed to write out requires" in gatsbyjs/gatsby?

Run `gatsby clean` then re-run the build.

Failed to write out requires

Error message

Failed to write out requires

What it means

The writeOutRequires step writes the generated requires file (which maps component/templates to their module paths for the SSR/query runtime) based on Redux store state. If writeAll throws -- typically a filesystem error or invalid state -- the panic wraps the underlying error.

Source

Thrown at packages/gatsby/src/services/write-out-requires.ts:20

import { writeAll } from "../bootstrap/requires-writer"
import { IQueryRunningContext } from "../state-machines/query-running/types"
import { assertStore } from "../utils/assert-store"

export async function writeOutRequires({
  store,
  parentSpan,
}: Partial<IQueryRunningContext>): Promise<void> {
  assertStore(store)

  // Write out files.
  const activity = reporter.activityTimer(`write out requires`, {
    parentSpan,
  })
  activity.start()
  try {
    await writeAll(store.getState())
  } catch (err) {
    reporter.panic(`Failed to write out requires`, err)
  }
  activity.end()
}

View on GitHub (pinned to 8b06340921)

Solutions

Run `gatsby clean` then re-run the build.
Inspect the attached `err` -- if it is a filesystem error (ENOENT, EACCES), resolve the permission/path/disk issue.
If the error references a specific component path, verify that file exists and the plugin/page referencing it is correct.
Check available disk space.

Defensive patterns

Strategy: try-catch

Validate before calling

// Verify store state integrity before write-out-requires
function validateStoreForWriteOut(store) {
  const state = store.getState()
  if (!state.components || !state.staticQueryComponents) {
    throw new Error('Store state missing components or staticQueryComponents')
  }
}

Try / catch

// The internal code already wraps writeAll in try/catch and panics.
// At the caller level, ensure disk space and permissions.
try {
  await writeOutRequires({ store, parentSpan })
} catch (err) {
  console.error('Write-out-requires failed:', err)
  // Clean and retry
  await cleanCache()
}

Prevention

Ensure sufficient disk space and write permissions in the project directory.
Run gatsby clean between builds on suspicion of cache corruption.
On Windows, exclude .cache from antivirus scanning.

When it happens

Trigger: writeAll(store.getState()) throws, which can happen on filesystem write errors, invalid/missing component paths in state, or a corrupted store state where components or static queries reference non-existent modules.

Common situations: Disk write permission or space issues in .cache. A plugin registered a component with a path that doesn't exist on disk. Corrupted Redux state after a crash. Antivirus locking files on Windows.

Related errors

AI-assisted analysis of gatsbyjs/gatsby@8b06340921 (2026-08-13). Data as JSON: /api/errors/d3d9443b1c97d271. Report an issue: GitHub.