error[E0793]: reference to packed field is unaligned

[wolewd]

error[E0793]: reference to packed field is unaligned
   --> /home/woelwd/.cargo/registry/src/index.crates.io-6f17d22bba15001f/rplidar_drv-0.6.0/src/ultra_capsuled_parser.rs:138:36
    |
138 |         let cabin_count = unsafe { prev_capsule.ultra_cabins.len() };
    |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: packed structs are only aligned by one byte, and many modern architectures penalize unaligned field accesses
    = note: creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
    = help: copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)

[wolewd]

Okay, since there is no response, I start to search for the solution by myself and finally get the solution. Replace line 138 in ultra_capsuled_parser.rs with this:

let ultra_cabins = prev_capsule.ultra_cabins;
let cabin_count = unsafe { ultra_cabins.len() };

Hopefully this can help people who had the same problem.