Builder version error when deploying

Hi, I’m not sure if this project is still tenable/maintained, but have just come back to an old codebase that previously used now-sapper and trying to get it redeploying to Vercel.

When running vercel we’re getting:

Error! Unsupported Builder version `undefined` from "vercel-sapper"
Error: Command "vercel build" exited with 1

Is this a known issue, or are there any potential workarounds? Thanks

---

For context:

Our package.json has a build command:

    "build": "sapper build --legacy",

vercel.json we’ve tried the legacy builds with and without config.build: false:

{
  "version": 2,
  "builds": [
    {
      "src": "package.json",
      "use": "vercel-sapper",
      "config": {
        "build": false
      }
    }
  ]
}

And .vercelignore includes __sapper__ directory:

/__sapper__
/cypress
!node_modules
/node_modules/*

[flyingelephant-web]

Thanks, @adamduncan. Did the same and deployed to vercel.

[swarnava]

@adamduncan Please reach out to [e-mail] with your deployment URL. We have disabled vercel builder for @janzheng and we would love to take a closer look for your deployment. Thanks!