New deployments s3 uploads fail with ERR_HTTP_HEADERS_SENT

[Naddiseo]

It seems like we're experiencing https://github.com/orgs/vercel/discussions/2204 again. We have the exact same symptoms.
If we redeploy a known working deployment we get the error with the new deployment but not the original.

pseudo-code of the failing code.

import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";
const s3 = new S3Client({
  region: process.env.AWS_S3_REGION,
  credentials: {
    accessKeyId: process.env.AWS_ACCESS_KEY,
    secretAccessKey: process.env.AWS_SECRET_KEY,
  },
});
const command = new PutObjectCommand({
      Bucket: process.env.AWS_S3_BUCKET,
      Key: file.key,
      ContentType: mimeType,
      ContentDisposition: `attachment; filename="testfile.pdf"`,
      Body: data,
    });

const response = await s3.send(command);

and the error we see

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
      at new NodeError (node:internal/errors:387:5)
      at ClientRequest.setHeader (node:_http_outgoing:644:11)
      at mod.request (/var/task/___vc/__launcher.js:90:17)
      at /var/task/node_modules/@aws-sdk/node-http-handler/dist-cjs/node-http-handler.js:72:25
      at new Promise (<anonymous>)
      at NodeHttpHandler.handle (/var/task/node_modules/@aws-sdk/node-http-handler/dist-cjs/node-http-handler.js:51:16)
      at processTicksAndRejections (node:internal/process/task_queues:96:5)
      at async /var/task/node_modules/@aws-sdk/middleware-serde/dist-cjs/deserializerMiddleware.js:5:26 {
    code: 'ERR_HTTP_HEADERS_SENT',
    '$metadata': { attempts: 1, totalRetryDelay: 0 }

( We've submitted a support case, but also posting in vercel discussions in case other people have the same issue )

[swarnava]

Hi,

We have pushed a fix for this. Thank you!