exclude build-time files

packages/nextjs/src/config/webpack.ts

@@ -5,6 +5,7 @@ import { default as SentryWebpackPlugin } from '@sentry/webpack-plugin';
 import * as chalk from 'chalk';
 import * as fs from 'fs';
 import * as path from 'path';
+import { WebpackPluginInstance } from 'webpack';
 
 import {
   BuildContext,
@@ -100,6 +101,22 @@ export function constructWebpackConfigFunction(
           ],
         });
       }
+
+      // Prevent `@vercel/nft` (which nextjs uses to determine which files are needed when packaging up a lambda) from
+      // including any of our build-time code or dependencies. (Otherwise it'll include files like this one and even the
+      // entirety of rollup and sucrase.)
+      const nftPlugin = newConfig.plugins?.find((plugin: WebpackPluginInstance) => {
+        const proto = Object.getPrototypeOf(plugin) as WebpackPluginInstance;
+        return proto.constructor.name === 'TraceEntryPointsPlugin';
+      }) as WebpackPluginInstance & { excludeFiles: string[] };
+      if (nftPlugin) {
+        nftPlugin.excludeFiles.push(path.join(__dirname, 'withSentryConfig.js'));
+      } else {
+        __DEBUG_BUILD__ &&
+          logger.warn(
+            'Unable to exclude Sentry build-time helpers from nft files. Could not find `TraceEntryPointsPlugin`.',
+          );
+      }
     }
 
     // The SDK uses syntax (ES6 and ES6+ features like object spread) which isn't supported by older browsers. For users