Next.js: Fix webpack fsCache not working

code/frameworks/nextjs/src/preset.ts

@@ -36,6 +36,19 @@ export const addons: PresetProperty<'addons'> = [
 export const core: PresetProperty<'core'> = async (config, options) => {
   const framework = await options.presets.apply('framework');
 
+  // Load the Next.js configuration before we need it in webpackFinal (below).
+  // This gives Next.js an opportunity to override some of webpack's internals
+  // (see next/dist/server/config-utils.js) before @storybook/builder-webpack5
+  // starts to use it. Without this, webpack's file system cache (fsCache: true)
+  // does not work.
+  const { nextConfigPath } = await options.presets.apply<FrameworkOptions>('frameworkOptions');
+  await configureConfig({
+    // Pass in a dummy webpack config object for now, since we don't want to
+    // modify the real one yet. We pass in the real one in webpackFinal.
+    baseConfig: {},
+    nextConfigPath,
+  });
+
   return {
     ...config,
     builder: {