Got some warning during build grin & grin-miner v0.5

Env:
Ubuntu 18.04
rust 1.31.1
grin & grin-miner v0.5

Build grin warning:

warning: unused import: crate::global
–> core/src/core/transaction.rs:21:5
|
21 | use crate::global;
| ^^^^^^^^^^^^^
|
= note: #[warn(unused_imports)] on by default

warning: unused import: BigEndian
–> core/src/core/transaction.rs:32:17
|
32 | use byteorder::{BigEndian, ByteOrder};
| ^^^^^^^^^

Compiling reqwest v0.9.5
warning: unused import: ByteOrder
–> core/src/core/transaction.rs:32:28
|
32 | use byteorder::{BigEndian, ByteOrder};
| ^^^^^^^^^

Build grin-miner warning:

warning: missing documentation for crate
–> plugin/src/lib.rs:15:1
|
15 | / #![deny(non_upper_case_globals)]
16 | | #![deny(non_camel_case_types)]
17 | | #![deny(non_snake_case)]
18 | | #![deny(unused_mut)]
… |
317 | | }
318 | | }
| |_^
|
note: lint level defined here
–> plugin/src/lib.rs:19:9
|
19 | #![warn(missing_docs)]
| ^^^^^^^^^^^^

warning: variant is never constructed: ParseError
–> cuckoo-miner/src/config/types.rs:60:2
|
60 | ParseError(String, String),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: #[warn(dead_code)] on by default

warning: variant is never constructed: FileNotFoundError
–> cuckoo-miner/src/config/types.rs:66:2
|
66 | FileNotFoundError(String),
| ^^^^^^^^^^^^^^^^^^^^^^^^^

warning: variant is never constructed: SerializationError
–> cuckoo-miner/src/config/types.rs:69:2
|
69 | SerializationError(String),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: method is never used: unload
–> cuckoo-miner/src/miner/types.rs:60:2
|
60 | pub fn unload(&mut self) {
| ^^^^^^^^^^^^^^^^^^^^^^^^

warning: constant item is never used: MAX_TARGET
–> cuckoo-miner/src/miner/util.rs:23:1
|
23 | const MAX_TARGET: [u8; 8] = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: function is never used: meets_difficulty
–> cuckoo-miner/src/miner/util.rs:48:1
|
48 | pub fn meets_difficulty(in_difficulty: u64, sol: Solution) -> bool {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Compiling grin_miner_config v0.5.0 (/home/john/coin/grin-miner/config)
Finished dev [unoptimized + debuginfo] target(s) in 2m 26s

Any thing missing here?