fix(DX): More precise error messages for export const config deprecation

packages/next/src/build/analysis/get-page-static-info.ts

@@ -527,7 +527,22 @@ export async function getPageStaticInfo(params: {
 
     if (pageType === 'app') {
       if (config) {
-        const message = `\`export const config\` in ${pageFilePath} is deprecated. Please change \`runtime\` property to segment export config. See https://nextjs.org/docs/app/api-reference/file-conventions/route-segment-config`
+        let message = `\`export const config\` in ${pageFilePath} is deprecated:`
+
+        if (config.runtime) {
+          message += `\n  - Change \`config.runtime…\` to \`export const runtime = ${JSON.stringify(
+            config.runtime
+          )}\``
+        }
+
+        if (config.regions) {
+          message += `\n  - Change \`config.regions…\` to \`export const preferredRegion = ${JSON.stringify(
+            config.regions
+          )}\``
+        }
+
+        message += `\nVisit https://nextjs.org/docs/app/api-reference/file-conventions/route-segment-config for more information.`
+
         if (isDev) {
           Log.warnOnce(message)
         } else {

test/e2e/app-dir-legacy-edge-runtime-config/app/legacy-runtime-config/page.js

@@ -9,4 +9,5 @@ export default function Page() {
 
 export const config = {
   runtime: 'edge',
+  regions: ['us-east-1'],
 }

test/e2e/app-dir-legacy-edge-runtime-config/index.test.ts

@@ -19,9 +19,16 @@ createNextDescribe(
       } else {
         expect(error).toBeDefined()
       }
-      expect(next.cliOutput).toContain('`export const config`')
+      expect(next.cliOutput).toContain('`export const config` in')
       expect(next.cliOutput).toContain(
-        'app/legacy-runtime-config/page.js is deprecated. Please change `runtime` property to segment export config. See https://nextjs.org/docs/app/api-reference/file-conventions/route-segment-config'
+        // the full path is more complex, we only care about this part
+        'app/legacy-runtime-config/page.js is deprecated'
+      )
+      expect(next.cliOutput).toContain(
+        '- Change `config.runtime…` to `export const runtime = "edge"'
+      )
+      expect(next.cliOutput).toContain(
+        '- Change `config.regions…` to `export const preferredRegion = ["us-east-1"]`'
       )
     })
   }