Source maps for next-on-pages cloudflare deployment don't show

[levi]

Hi,

I recently migrated my next.js app to Cloudflare's pages platform, using their @cloudflare/next-on-pages adapter.

Sentry works great, but I can't seem to get the stack traces in production to map to source maps:

My configuration is fairly vanilla, using the default sentry configuration from the source map wizard. Since next-on-pages simulates a vercel edge runtime environment, I am wondering if there's anything extra I need to do to generate source maps for the edge runtime? My build environment uses the sentry auth token to register a build with sentry, so was assuming source maps were being uploading, but honestly not quite sure how to debug this.

Here's my next.config.mjs:

export default withSentryConfig(
  config,
  {
    // For all available options, see:
    // https://github.com/getsentry/sentry-webpack-plugin#options

    // Suppresses source map uploading logs during build
    silent: true,
    org: "org",
    project: "project",
  },
  {
    // For all available options, see:
    // https://docs.sentry.io/platforms/javascript/guides/nextjs/manual-setup/

    // Upload a larger set of source maps for prettier stack traces (increases build time)
    widenClientFileUpload: true,

    // Transpiles SDK to be compatible with IE11 (increases bundle size)
    transpileClientSDK: true,

    // Routes browser requests to Sentry through a Next.js rewrite to circumvent ad-blockers. (increases server load)
    // Note: Check that the configured route will not match with your Next.js middleware, otherwise reporting of client-
    // side errors will fail.
    tunnelRoute: "/monitoring",

    // Hides source maps from generated client bundles
    hideSourceMaps: true,

    // Automatically tree-shake Sentry logger statements to reduce bundle size
    disableLogger: true,

    // Enables automatic instrumentation of Vercel Cron Monitors.
    // See the following for more information:
    // https://docs.sentry.io/product/crons/
    // https://vercel.com/docs/cron-jobs
    automaticVercelMonitors: true,
  },
);

[levi]

Seems like my sourcemap uploads maps to files like:

~/_next/static/chunks/1249.d9777ee89355e4b6.js

While the errors reported come out of the cloudflare pages like this:

__next-on-pages-dist__/webpack/62d6966c94b522734ceb09853b489431.js

Investigating a way to create sourcemaps for the additional build step. Any insight would be super helpful!

[levi]

I got my answer, Cloudflare Pages (via @cloudflare/next-on-pages) doesn't support source maps at the moment and likely never will due to how they minify and dedupe the built code. More info here: cloudflare/next-on-pages#724