error: captured variable cannot escape `FnMut` closure body
   --> src/main.rs:387:86
    |
386 |                       let mut err: Option<Box<dyn std::error::Error>> = None;
    |                           ------- variable defined here
387 |                       let mut k = Box::pin(get_all_bans(sql_pool).await.filter_map(|r| async {
    |  ____________________________________________________________________________________-_^
    | |                                                                                    |
    | |                                                                                    inferred to be a `FnMut` closure
388 | |                         match r {
389 | |                             Ok(b) => Some(row![
390 | |                                 cell!(b.ip.to_string()),
...   |
399 | |                                 err = Some(Box::new(e));
    | |                                 --- variable captured here
...   |
402 | |                         }
403 | |                     }));
    | |_____________________^ returns an `async` block that contains a reference to a captured variable, which then escapes the closure body
    |
    = note: `FnMut` closures only have access to their captured variables while they are executing...
    = note: ...therefore, they cannot allow references to captured variables to escape