[INFO] cloning repository https://github.com/murphym18/huffman_code
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/murphym18/huffman_code" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmurphym18%2Fhuffman_code", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmurphym18%2Fhuffman_code'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f3ea7042d973b2b4d28d24284e0d37efc1867cb3
[INFO] checking murphym18/huffman_code against try#3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f for pr-87248
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmurphym18%2Fhuffman_code" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/murphym18/huffman_code on toolchain 3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/murphym18/huffman_code
[INFO] finished tweaking git repo https://github.com/murphym18/huffman_code
[INFO] tweaked toml for git repo https://github.com/murphym18/huffman_code written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/murphym18/huffman_code already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e6fec8c73c68b924fbdd81cfc78281c70a04bc9959ebadd6abcbc659cc9a9091
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "e6fec8c73c68b924fbdd81cfc78281c70a04bc9959ebadd6abcbc659cc9a9091", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e6fec8c73c68b924fbdd81cfc78281c70a04bc9959ebadd6abcbc659cc9a9091", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e6fec8c73c68b924fbdd81cfc78281c70a04bc9959ebadd6abcbc659cc9a9091", kill_on_drop: false }`
[INFO] [stdout] e6fec8c73c68b924fbdd81cfc78281c70a04bc9959ebadd6abcbc659cc9a9091
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+3e59a8c2f14152ccc92a6c079f592dc2dc6fa93f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b63126046c7e6559c176c60a2b3a51216b9df29f2a947aa129c2433b8fdddb1f
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b63126046c7e6559c176c60a2b3a51216b9df29f2a947aa129c2433b8fdddb1f", kill_on_drop: false }`
[INFO] [stderr]     Checking huffman_code v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/lib.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Cursor`
[INFO] [stdout]  --> src/lib.rs:5:28
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::io::{Read, Write, Cursor};
[INFO] [stdout]   |                            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:70:21
[INFO] [stdout]    |
[INFO] [stdout] 70 |     pub output: Box<Write>,
[INFO] [stdout]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:76:29
[INFO] [stdout]    |
[INFO] [stdout] 76 |     pub fn wrap(output: Box<Write>) -> BitWriter {
[INFO] [stdout]    |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:110:16
[INFO] [stdout]     |
[INFO] [stdout] 110 |     input: Box<Read>,
[INFO] [stdout]     |                ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/lib.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:116:23
[INFO] [stdout]     |
[INFO] [stdout] 116 |     fn new(input: Box<Read>) -> BitReader {
[INFO] [stdout]     |                       ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:253:28
[INFO] [stdout]     |
[INFO] [stdout] 253 | fn read_u64_be(input: &mut Read) -> u64 {
[INFO] [stdout]     |                            ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:266:38
[INFO] [stdout]     |
[INFO] [stdout] 266 | fn read_one_table_record(input: &mut Read) -> Tree {
[INFO] [stdout]     |                                      ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:287:30
[INFO] [stdout]     |
[INFO] [stdout] 287 | fn read_one_byte(input: &mut Read) -> u8 {
[INFO] [stdout]     |                              ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:365:38
[INFO] [stdout]     |
[INFO] [stdout] 365 | fn write_compressed_data(input: &mut Read, output: &mut BitWriter, table: &HashMap<u8, BitString>) {
[INFO] [stdout]     |                                      ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:442:39
[INFO] [stdout]     |
[INFO] [stdout] 442 | fn count_byte_occurrences(input: &mut Read) -> [u64; 256] {
[INFO] [stdout]     |                                       ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Cursor`
[INFO] [stdout]  --> src/lib.rs:5:28
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::io::{Read, Write, Cursor};
[INFO] [stdout]   |                            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:70:21
[INFO] [stdout]    |
[INFO] [stdout] 70 |     pub output: Box<Write>,
[INFO] [stdout]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:76:29
[INFO] [stdout]    |
[INFO] [stdout] 76 |     pub fn wrap(output: Box<Write>) -> BitWriter {
[INFO] [stdout]    |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:110:16
[INFO] [stdout]     |
[INFO] [stdout] 110 |     input: Box<Read>,
[INFO] [stdout]     |                ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:116:23
[INFO] [stdout]     |
[INFO] [stdout] 116 |     fn new(input: Box<Read>) -> BitReader {
[INFO] [stdout]     |                       ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:253:28
[INFO] [stdout]     |
[INFO] [stdout] 253 | fn read_u64_be(input: &mut Read) -> u64 {
[INFO] [stdout]     |                            ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:266:38
[INFO] [stdout]     |
[INFO] [stdout] 266 | fn read_one_table_record(input: &mut Read) -> Tree {
[INFO] [stdout]     |                                      ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:287:30
[INFO] [stdout]     |
[INFO] [stdout] 287 | fn read_one_byte(input: &mut Read) -> u8 {
[INFO] [stdout]     |                              ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:365:38
[INFO] [stdout]     |
[INFO] [stdout] 365 | fn write_compressed_data(input: &mut Read, output: &mut BitWriter, table: &HashMap<u8, BitString>) {
[INFO] [stdout]     |                                      ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/lib.rs:442:39
[INFO] [stdout]     |
[INFO] [stdout] 442 | fn count_byte_occurrences(input: &mut Read) -> [u64; 256] {
[INFO] [stdout]     |                                       ^^^^ help: use `dyn`: `dyn Read`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `left`
[INFO] [stdout]    --> src/lib.rs:171:22
[INFO] [stdout]     |
[INFO] [stdout] 171 |         Node {count, ref left, ref right} => count,
[INFO] [stdout]     |                      ^^^^^^^^ help: try ignoring the field: `left: _`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `right`
[INFO] [stdout]    --> src/lib.rs:171:32
[INFO] [stdout]     |
[INFO] [stdout] 171 |         Node {count, ref left, ref right} => count,
[INFO] [stdout]     |                                ^^^^^^^^^ help: try ignoring the field: `right: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]    --> src/lib.rs:172:22
[INFO] [stdout]     |
[INFO] [stdout] 172 |         Leaf {count, value} => count
[INFO] [stdout]     |                      ^^^^^ help: try ignoring the field: `value: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:178:15
[INFO] [stdout]     |
[INFO] [stdout] 178 |         Node {count, ref left, ref right} => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:235:19
[INFO] [stdout]     |
[INFO] [stdout] 235 |             Leaf {count, value} => {
[INFO] [stdout]     |                   ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:240:19
[INFO] [stdout]     |
[INFO] [stdout] 240 |             Node {count, ref left, ref right} => {
[INFO] [stdout]     |                   ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `p`
[INFO] [stdout]    --> src/lib.rs:303:9
[INFO] [stdout]     |
[INFO] [stdout] 303 |     let p = 97 as u8;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_p`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]    --> src/lib.rs:346:26
[INFO] [stdout]     |
[INFO] [stdout] 346 |             Leaf {count, value} => size = size + count,
[INFO] [stdout]     |                          ^^^^^ help: try ignoring the field: `value: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:395:15
[INFO] [stdout]     |
[INFO] [stdout] 395 |         Node {count, ref left, ref right} => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:403:15
[INFO] [stdout]     |
[INFO] [stdout] 403 |         Leaf {count, value}  => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:215:9
[INFO] [stdout]     |
[INFO] [stdout] 215 |     let mut tree = make_tree(table_vec);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:300:9
[INFO] [stdout]     |
[INFO] [stdout] 300 |     let mut tree = make_tree(v);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:350:9
[INFO] [stdout]     |
[INFO] [stdout] 350 |     let mut buf: [u8; 8] = unsafe {
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:388:9
[INFO] [stdout]     |
[INFO] [stdout] 388 |     let mut bits = BitString::new();
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:393:29
[INFO] [stdout]     |
[INFO] [stdout] 393 | fn traverse(current: &Tree, mut bits: BitString, table: &mut HashMap<u8, BitString>) {
[INFO] [stdout]     |                             ----^^^^
[INFO] [stdout]     |                             |
[INFO] [stdout]     |                             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `left`
[INFO] [stdout]    --> src/lib.rs:171:22
[INFO] [stdout]     |
[INFO] [stdout] 171 |         Node {count, ref left, ref right} => count,
[INFO] [stdout]     |                      ^^^^^^^^ help: try ignoring the field: `left: _`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `right`
[INFO] [stdout]    --> src/lib.rs:171:32
[INFO] [stdout]     |
[INFO] [stdout] 171 |         Node {count, ref left, ref right} => count,
[INFO] [stdout]     |                                ^^^^^^^^^ help: try ignoring the field: `right: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]    --> src/lib.rs:172:22
[INFO] [stdout]     |
[INFO] [stdout] 172 |         Leaf {count, value} => count
[INFO] [stdout]     |                      ^^^^^ help: try ignoring the field: `value: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:178:15
[INFO] [stdout]     |
[INFO] [stdout] 178 |         Node {count, ref left, ref right} => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:235:19
[INFO] [stdout]     |
[INFO] [stdout] 235 |             Leaf {count, value} => {
[INFO] [stdout]     |                   ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:240:19
[INFO] [stdout]     |
[INFO] [stdout] 240 |             Node {count, ref left, ref right} => {
[INFO] [stdout]     |                   ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `p`
[INFO] [stdout]    --> src/lib.rs:303:9
[INFO] [stdout]     |
[INFO] [stdout] 303 |     let p = 97 as u8;
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_p`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]    --> src/lib.rs:346:26
[INFO] [stdout]     |
[INFO] [stdout] 346 |             Leaf {count, value} => size = size + count,
[INFO] [stdout]     |                          ^^^^^ help: try ignoring the field: `value: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:395:15
[INFO] [stdout]     |
[INFO] [stdout] 395 |         Node {count, ref left, ref right} => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `count`
[INFO] [stdout]    --> src/lib.rs:403:15
[INFO] [stdout]     |
[INFO] [stdout] 403 |         Leaf {count, value}  => {
[INFO] [stdout]     |               ^^^^^ help: try ignoring the field: `count: _`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `byte_string`
[INFO] [stdout]    --> src/lib.rs:138:4
[INFO] [stdout]     |
[INFO] [stdout] 138 | fn byte_string(data: u8, num_bits: u8) -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:215:9
[INFO] [stdout]     |
[INFO] [stdout] 215 |     let mut tree = make_tree(table_vec);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:273:16
[INFO] [stdout]     |
[INFO] [stdout] 273 |         panic!(error_message);
[INFO] [stdout]     |                ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]     |
[INFO] [stdout] 273 |         panic!("{}", error_message);
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]     |
[INFO] [stdout] 273 |         std::panic::panic_any(error_message);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |         self.output.write(&a);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:236:17
[INFO] [stdout]     |
[INFO] [stdout] 236 |                 output.write(&[value]);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:306:5
[INFO] [stdout]     |
[INFO] [stdout] 306 |     f.seek(SeekFrom::Start(0));
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:321:5
[INFO] [stdout]     |
[INFO] [stdout] 321 |     output.write_all(&list_len_buf);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:334:17
[INFO] [stdout]     |
[INFO] [stdout] 334 |                 output.write_all(&buf);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:353:5
[INFO] [stdout]     |
[INFO] [stdout] 353 |     output.write_all(&buf);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:300:9
[INFO] [stdout]     |
[INFO] [stdout] 300 |     let mut tree = make_tree(v);
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:350:9
[INFO] [stdout]     |
[INFO] [stdout] 350 |     let mut buf: [u8; 8] = unsafe {
[INFO] [stdout]     |         ----^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:388:9
[INFO] [stdout]     |
[INFO] [stdout] 388 |     let mut bits = BitString::new();
[INFO] [stdout]     |         ----^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:393:29
[INFO] [stdout]     |
[INFO] [stdout] 393 | fn traverse(current: &Tree, mut bits: BitString, table: &mut HashMap<u8, BitString>) {
[INFO] [stdout]     |                             ----^^^^
[INFO] [stdout]     |                             |
[INFO] [stdout]     |                             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `byte_string`
[INFO] [stdout]    --> src/lib.rs:138:4
[INFO] [stdout]     |
[INFO] [stdout] 138 | fn byte_string(data: u8, num_bits: u8) -> String {
[INFO] [stdout]     |    ^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:273:16
[INFO] [stdout]     |
[INFO] [stdout] 273 |         panic!(error_message);
[INFO] [stdout]     |                ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]     |
[INFO] [stdout] 273 |         panic!("{}", error_message);
[INFO] [stdout]     |                ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]     |
[INFO] [stdout] 273 |         std::panic::panic_any(error_message);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 34 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |         self.output.write(&a);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:236:17
[INFO] [stdout]     |
[INFO] [stdout] 236 |                 output.write(&[value]);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:306:5
[INFO] [stdout]     |
[INFO] [stdout] 306 |     f.seek(SeekFrom::Start(0));
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:321:5
[INFO] [stdout]     |
[INFO] [stdout] 321 |     output.write_all(&list_len_buf);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:334:17
[INFO] [stdout]     |
[INFO] [stdout] 334 |                 output.write_all(&buf);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:353:5
[INFO] [stdout]     |
[INFO] [stdout] 353 |     output.write_all(&buf);
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 34 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.43s
[INFO] running `Command { std: "docker" "inspect" "b63126046c7e6559c176c60a2b3a51216b9df29f2a947aa129c2433b8fdddb1f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b63126046c7e6559c176c60a2b3a51216b9df29f2a947aa129c2433b8fdddb1f", kill_on_drop: false }`
[INFO] [stdout] b63126046c7e6559c176c60a2b3a51216b9df29f2a947aa129c2433b8fdddb1f