[LayaAir 2.0]mac laya 2.5beta ts示例工程 tsconfig.json tartget 改成es5 编译报错

开始编译: Wed Mar 11 2020 09:09:51 GMT+0800 (CST)
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[09:09:53] Working directory changed to /Applications/LayaAirIDE_beta.app/Contents/Resources/app
[09:09:54] Using gulpfile ~/projects/mylaya11/Tank/.laya/compile.js
[09:09:54] Starting 'compile'...
{ Error: /Users/xxxxx/projects/mylaya11/Tank/src/script/Bullet.ts(4,29): semantic error TS2354: This syntax requires an imported helper but module 'tslib' cannot be found.
at error (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup/dist/rollup.js:9402:30)
at Object.error (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup/dist/rollup.js:15621:24)
at Object.error (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup/dist/rollup.js:16065:38)
at RollupContext.error (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:17187:30)
at lodash_3 (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:24954:23)
at arrayEach (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:532:11)
at forEach (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:9360:14)
at printDiagnostics (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:24927:5)
at Object.transform (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup-plugin-typescript2/dist/rollup-plugin-typescript2.cjs.js:26760:17)
at Promise.resolve.then (/Applications/LayaAirIDE_beta.app/Contents/Resources/app/node_modules/rollup/dist/rollup.js:15768:25)
id: '/Users/xxxxx/projects/mylaya11/Tank/src/script/Bullet.ts',
hook: 'transform',
code: 'PLUGIN_ERROR',
plugin: 'rpt2' }
 
node版本：v8.17.0
tsc版本：Version 3.9.0