[BUG] Not able to deploy on vercel

Platform

Vercel

Browser

Chrome 137

Current Behavior

While deploying to Vercel i am getting below error. The environment variables are in place.

opencut:build: https://nextjs.org/telemetry
opencut:build:
opencut:build: ▲ Next.js 15.4.1
opencut:build:
opencut:build: Creating an optimized production build ...
opencut:build: [webpack.cache.PackFileCacheStrategy] Serializing big strings (128kiB) impacts deserialization performance (consider using Buffer instead and decode when needed)
opencut:build: ✓ Compiled successfully in 33.0s
opencut:build: Linting and checking validity of types ...
opencut:build: 2 | import { toNextJsHandler } from "better-auth/next-js";
opencut:build: 3 |
opencut:build: 4 | export const { POST, GET } = toNextJsHandler(auth);
opencut:build: Next.js build worker exited with code: 1 and signal: null
opencut:build: error: script "build" exited with code 1
opencut:build: ERROR: command finished with error: command (/vercel/path0/apps/web) /bun1/bun run build exited (1)
opencut#build: command (/vercel/path0/apps/web) /bun1/bun run build exited (1)
Tasks: 0 successful, 1 total
Cached: 0 cached, 1 total
Time: 51.111s
Summary: /vercel/path0/.turbo/runs/2zxT3hXZkYOEfW2UsG0pbIH2Toi.json
Failed: opencut#build
ERROR run failed: command exited (1)
error: script "build" exited with code 1
Error: Command "bun run build" exited with 1
Exiting build container

Expected Behavior

Deployment should be successful.

Recurrence Probability

Always

Steps To Reproduce

Click on deploy button given in readme.

Anything else?

No response

Start with the README deploy flow and reproduce the failure using the apps/web Bun build command. Inspect the reported build and type-check failure around the better-auth/next-js handler, then verify that the Vercel deployment completes successfully.