我试图将一个平均堆栈项目推送到heroku，但它不会在heroku的服务器上启动。它不断从应用程序日志中提供以下内容：
2017-12-12T23:59:32.528690+00:00 app[web.1]: npm ERR! syscall spawn
2017-12-12T23:59:32.529607+00:00 app[web.1]: npm ERR! atl@0.0.0 start:
`ng serve`
2017-12-12T23:59:32.529706+00:00 app[web.1]: npm ERR! spawn ENOENT
2017-12-12T23:59:32.529925+00:00 app[web.1]: npm ERR!
2017-12-12T23:59:32.530127+00:00 app[web.1]: npm ERR! Failed at the
atl@0.0.0 start script.
2017-12-12T23:59:32.530306+00:00 app[web.1]: npm ERR! This is probably
not a problem with npm. There is likely additional logging output
above.
2017-12-12T23:59:32.535107+00:00 app[web.1]:
2017-12-12T23:59:32.535281+00:00 app[web.1]: npm ERR! A complete log
of this run can be found in:
2017-12-12T23:59:32.535429+00:00 app[web.1]: npm ERR!
/app/.npm/_logs/2017-12-12T23_59_32_531Z-debug.log
2017-12-12T23:59:32.626726+00:00 heroku[web.1]: State changed from
starting to crashed
2017-12-12T23:59:32.613442+00:00 heroku[web.1]: Process exited with
status 1
我不知道在哪里寻找这个问题，如果我需要上传任何文件以帮助解决此错误，请告诉我，请提前感谢。