No DAG parsing error while runing "airflow dags list" in airflow 2.0

[forestlzj]

Apache Airflow version:
2.0

Kubernetes version (if you are using kubernetes) (use kubectl version):

Environment:

• Cloud provider or hardware configuration: hp gen380 32c, 192g ram
• OS (e.g. from /etc/os-release): centos 7.3
• Kernel (e.g. uname -a):
• Install tools:
• Others:

What happened:
before 2.0, the command "airflow list_dags" will show the error of parsing a DAG, which help developer to find any syntax error. but for 2.0, the command “airflow dags list" only show the DAG parsed correctly. No any hints for the DAG parsed failed.

What you expected to happen:
somewhere to show the error of parsing a specify DAG

How to reproduce it:
create a DAG with syntax error, then run "airflow dags list"

Anything else we need to know:

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template!

[mik-laj]

Done via: #13180