Handle specific exceptions

The `jobinfo` script contains many `try ... except Exception as e` blocks.
It would be better practice to set up specific handlers for expected error types (e.g., `KeyError`), only, so that unexpected ones are properly raised to the user's notice.

Start by locating the jobinfo script and reviewing each try ... except Exception as e block, noting which expected error types each operation can raise. Replace broad handling with specific handlers for those expected types while allowing unexpected exceptions to surface; done means all such blocks have been reviewed and unexpected errors are no longer hidden.

Written by the indexing model from the issue text.