Comment by more-nitor

hmm this might be solved in some simple ways:

1. create `with_err` function: some_mayerr_func().with_err_log()?

2. add 'newbie beginner mode(default)' / 'expert mode (optimized)' for rust:

- current Rust default is a bit too focused on code-optimization, too much so that it defaults to removing backtrace

- default should be 'show every backtrace even for handled errors (in my code, not the lib code -- bonus points for "is handled" checkbox)'