We log the possible causes here. I checked your build logs and I'm seeing an out of memory issue, so if you haven't touched anything else I think you're falling into the "can also be caused by a Next.js build failure" case
You have a two options
- upgrade to get higher memory limits
- reduce the memory usage during build
I suspect it's the Sentry sourcemap generation that is using most of the memory. Try disabling that temporarily to see if it unblocks builds, and if so you may be able to configure it to use less memory
https://err.sh/vercel/vercel/now-next-routes-manifest