Flask reports an error runtimeerror: the session is unavailable because no secret key was set

RuntimeError: The session is unavailable because no secret key was set. Set the secret_key on the application to something unique and secret.

When we're in liunx Running on the system Flask When the project is , When you encounter this error ：

resolvent ：

Basically, it is said on the Internet , stay Flask object app Set below SECRET_KEY：
Added to the startup file of my project , I can window10 Successfully run the project under , stay liunx The system fails or reports an error

Added to the startup file of my project here linux Can successfully run