fix: sync override settings

.changeset/tender-wasps-shop.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Improves syncing

packages/astro/src/assets/fonts/vite-plugin-fonts.ts

@@ -67,7 +67,7 @@ interface Options {
 }
 
 export function fontsPlugin({ settings, sync, logger }: Options): Plugin {
-	if (sync || !settings.config.experimental.fonts) {
+	if (!settings.config.experimental.fonts) {
 		// This is required because the virtual module may be imported as
 		// a side effect
 		// TODO: remove once fonts are stabilized
@@ -319,7 +319,7 @@ export function fontsPlugin({ settings, sync, logger }: Options): Plugin {
 			}
 		},
 		async buildEnd() {
-			if (settings.config.experimental.fonts!.length === 0) {
+			if (sync || settings.config.experimental.fonts!.length === 0) {
 				cleanup();
 				return;
 			}

packages/astro/src/core/sync/index.ts

@@ -251,7 +251,26 @@ async function syncContentCollections(
 				ssr: { external: [] },
 				logLevel: 'silent',
 			},
-			{ settings, logger, mode, command: 'build', fs, sync: true, routesList, manifest },
+			{
+				// Prevent mutation of specific properties by vite plugins during sync
+				settings: {
+					...settings,
+					// Prevent mutation by vite plugins during sync
+					buildOutput: undefined,
+					// Sync causes font resources and style hashes to be duplicated
+					injectedCsp: {
+						fontResources: new Set(),
+						styleHashes: [],
+					},
+				},
+				logger,
+				mode,
+				command: 'build',
+				fs,
+				sync: true,
+				routesList,
+				manifest,
+			},
 		),
 	);