F401 false positive in try except ImportError

[Skylion007]

F401 delete an import statement used to check whether a module is installed:

 try:
     import slack_sdk
     del slack_sdk
 except ImportError as e:
     raise MissingConditionalImportError('health_checker', 'slack_sdk', None) from e

Code snippet from https://github.com/mosaicml/composer
This auto fix just removed the import statement which creates an error when it is run again.

     try:
         del slack_sdk
     except ImportError as e:
         raise MissingConditionalImportError('health_checker', 'slack_sdk', None) from e

Obviously, the new code is a bad fix.

[charliermarsh]

I thought we handled this case (try-catch with ImportError) explicitly. It’s supposed to flag, but not autofix.

[charliermarsh]

Guessing it’s related to the del but I’ll have to test.