vercel/next.js · error

Skipping heap snapshot generation since heap snapshot has al

Error message

Skipping heap snapshot generation since heap snapshot has already been generated.

What it means

traceMemoryUsage guards snapshot generation with the alreadyGeneratedHeapSnapshot flag: on subsequent threshold crossings it warns that generation is skipped so only one (potentially very large) .heapsnapshot file is produced per run.

Source

Thrown at packages/next/src/lib/memory/trace.ts:119

      warn(
        bold(
          `Heap usage is close to the limit. ${percentageHeapUsed.toFixed(
            2
          )}% of heap has been used.`
        )
      )
      if (!alreadyGeneratedHeapSnapshot) {
        warn(
          bold(
            `Saving heap snapshot to ${heapFilename}.  ${italic(
              'Note: this will take some time.'
            )}`
          )
        )
        v8.writeHeapSnapshot(heapFilename)
        alreadyGeneratedHeapSnapshot = true
      } else {
        warn(
          'Skipping heap snapshot generation since heap snapshot has already been generated.'
        )
      }
    }
  }
}

View on GitHub (pinned to 0eb3775416)

Solutions

1. A heap snapshot already exists for this run; delete the previous snapshot if you need a fresh one.

When it happens

Trigger: Thrown at packages/next/src/lib/memory/trace.ts:119 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/next.js@0eb3775416 (2026-08-19). Data as JSON: /api/errors/e1f46ea61254f5f8. Report an issue: GitHub.