fix: only show prerendering message when actually prerendering (#8809)

Also add "Building app" and "Analysing routes" log. Hopefully clears up some confusion around what happens at build time.

Author: dummdidumm

.changeset/bright-moles-worry.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: only show prerendering message when actually prerendering

packages/kit/src/core/postbuild/prerender.js

@@ -361,6 +361,15 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 		saved.set(file, dest);
 	}
 
+	if (
+		config.prerender.entries.length > 1 ||
+		config.prerender.entries[0] !== '*' ||
+		prerender_map.size > 0
+	) {
+		// Only log if we're actually going to do something to not confuse users
+		log.info('Prerendering');
+	}
+
 	for (const entry of config.prerender.entries) {
 		if (entry === '*') {
 			for (const [id, prerender] of prerender_map) {

packages/kit/src/exports/vite/index.js

@@ -596,13 +596,17 @@ function kit({ svelte_config }) {
 				);
 
 				// first, build server nodes without the client manifest so we can analyse it
+				log.info('Analysing routes');
+
 				build_server_nodes(out, kit, manifest_data, server_manifest, null, null);
 
 				const metadata = await analyse({
 					manifest_path,
 					env: { ...env.private, ...env.public }
 				});
 
+				log.info('Building app');
+
 				// create client build
 				write_client_manifest(
 					kit,
@@ -649,8 +653,6 @@ function kit({ svelte_config }) {
 				build_server_nodes(out, kit, manifest_data, server_manifest, client_manifest, css);
 
 				// ...and prerender
-				log.info('Prerendering');
-
 				const { prerendered, prerender_map } = await prerender({
 					out,
 					manifest_path,