chore: add error log when entryPagePath not found

packages/uni-cli-shared/lib/preprocess.js

 const DEFAULT_KEYS = [
+  'VUE2',
+  'VUE3',
   'MP',
   'APP',
   'APP-PLUS-NVUE',
@@ -25,6 +27,8 @@ module.exports = function initPreprocess (name, platforms, userDefines = {}) {
       defaultContext[normalize(name)] = false
     })
 
+  defaultContext.VUE2 = true
+
   vueContext[normalize(name)] = true
 
   if (name === 'app-plus') {

src/platforms/app-plus/service/framework/config.js

@@ -76,6 +76,7 @@ export function initEntryPage () {
   const entryRoute = '/' + entryPagePath
   const routeOptions = __uniRoutes.find(route => route.path === entryRoute)
   if (!routeOptions) {
+    console.error(`[uni-app] ${entryPagePath} not found...`)
     return
   }