Fix pages index normalization for --debug-build-paths

crates/next-api/src/project.rs

@@ -253,17 +253,31 @@ impl DebugBuildPathsRouteKeys {
                 .iter()
                 .map(|path| {
                     // Pages router: "/foo.tsx" -> "/foo"
+                    // Also: "/foo/index.tsx" -> "/foo" (strip "/index" suffix).
                     // Catch-all routes like "/foo/[...slug]" contain dots in the segment name;
                     // only treat the suffix as an extension when it is a plain alphanumeric token.
                     let file_name = path.rsplit('/').next().unwrap_or(path);
-                    if let Some(dot_idx) = file_name.rfind('.') {
+                    let mut result: RcStr = if let Some(dot_idx) = file_name.rfind('.') {
                         let ext = &file_name[dot_idx + 1..];
                         if !ext.is_empty() && ext.chars().all(|c| c.is_ascii_alphanumeric()) {
                             let trimmed_len = path.len() - (file_name.len() - dot_idx);
-                            return path[..trimmed_len].into();
+                            path[..trimmed_len].into()
+                        } else {
+                            path.clone()
                         }
+                    } else {
+                        path.clone()
+                    };
+
+                    if let Some(stripped) = result.strip_suffix("/index") {
+                        result = if stripped.is_empty() {
+                            "/".into()
+                        } else {
+                            stripped.into()
+                        };
                     }
-                    path.clone()
+
+                    result
                 })
                 .collect(),
         })

test/production/debug-build-path/debug-build-paths.test.ts

@@ -28,6 +28,20 @@ describe('debug-build-paths', () => {
         expect(buildResult.cliOutput).not.toContain('Route (app)')
       })
 
+      it('should include pages index routes with debug-prerender', async () => {
+        const buildResult = await next.build({
+          args: ['--debug-prerender', '--debug-build-paths', 'pages/**'],
+        })
+        expect(buildResult.exitCode).toBe(0)
+        expect(buildResult.cliOutput).toBeDefined()
+
+        expect(buildResult.cliOutput).toContain('Route (pages)')
+        expect(buildResult.cliOutput).toContain('○ /with-index')
+        expect(buildResult.cliOutput).not.toContain(
+          'Cannot find module for page'
+        )
+      })
+
       it('should build multiple pages routes', async () => {
         const buildResult = await next.build({
           args: ['--debug-build-paths', 'pages/foo.tsx,pages/bar.tsx'],

test/production/debug-build-path/fixtures/default/pages/with-index/index.tsx

@@ -0,0 +1,3 @@
+export default function WithIndexPage() {
+  return <main>With index page</main>
+}