Env from .cur+env is used when specifying an illegal one

[fmauch]

When change_environment is called with a non-existing environment, an error is thrown, but the command then falls back to sourcing what was in the .cur_env file before.

[fmauch]

@Oberacda, since you reported this to me directly: I cannot reproduce this:

ubuntu@jammy ~> $ fzirob change_environment fsgfhgdhdg                                                                                                                                                                                                                                                                                   
rob_folders change_environment fsgfhgdhdg
No environment with name < fsgfhgdhdg > found.
Execution of module 'EnvironmentChoice' failed. Error message:
'unknown environment'
                                                                                                                                                                                                                                                                                                                            
ubuntu@jammy ~> $ echo $?                                                                                                                                                                                                                                                                                                                
1
                                                                                                                                                                                                                                                                                                                            
ubuntu@jammy ~> $ cat checkout/.cur_env                                                                                                                                                                                                                                                                                                  
ur_rolling%

Did I understand something wrong?