[INFO] cloning repository https://github.com/AlexisInsMu/huffman_coder
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AlexisInsMu/huffman_coder" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexisInsMu%2Fhuffman_coder", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexisInsMu%2Fhuffman_coder'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e1e3092d77f3c16a29191b9689c351f5a853834b
[INFO] testing AlexisInsMu/huffman_coder against beta-2025-09-21 for beta-1.91-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexisInsMu%2Fhuffman_coder" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/AlexisInsMu/huffman_coder
[INFO] finished tweaking git repo https://github.com/AlexisInsMu/huffman_coder
[INFO] tweaked toml for git repo https://github.com/AlexisInsMu/huffman_coder written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/AlexisInsMu/huffman_coder on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/AlexisInsMu/huffman_coder already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 633d7bb3d9b0a859d1e2e2a8eb0b914d5bcc132793b452e8caa9e2a9f167bde6
[INFO] running `Command { std: "docker" "start" "-a" "633d7bb3d9b0a859d1e2e2a8eb0b914d5bcc132793b452e8caa9e2a9f167bde6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "633d7bb3d9b0a859d1e2e2a8eb0b914d5bcc132793b452e8caa9e2a9f167bde6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "633d7bb3d9b0a859d1e2e2a8eb0b914d5bcc132793b452e8caa9e2a9f167bde6", kill_on_drop: false }`
[INFO] [stdout] 633d7bb3d9b0a859d1e2e2a8eb0b914d5bcc132793b452e8caa9e2a9f167bde6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fc3c145acc59a3bfd0c274ee36d16406e4c3c5e5733d2eb131d5f48bf509fa55
[INFO] running `Command { std: "docker" "start" "-a" "fc3c145acc59a3bfd0c274ee36d16406e4c3c5e5733d2eb131d5f48bf509fa55", kill_on_drop: false }`
[INFO] [stderr]    Compiling huffman_coder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `codes`
[INFO] [stdout]    --> src/lib.rs:107:10
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_codes`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]    --> src/lib.rs:107:18
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |                  ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> src/lib.rs:156:12
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]     = help: consider replacing the `if let` with a `let`
[INFO] [stdout]     = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iscorrect`
[INFO] [stdout]    --> src/lib.rs:156:16
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |                ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iscorrect`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file_name`
[INFO] [stdout]    --> src/lib.rs:126:28
[INFO] [stdout]     |
[INFO] [stdout] 126 | pub fn encode(input: &str, file_name: String) -> i64 {
[INFO] [stdout]     |                            ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_file_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `deserialize` is never used
[INFO] [stdout]   --> src/lib.rs:48:12
[INFO] [stdout]    |
[INFO] [stdout] 15 | impl Node{
[INFO] [stdout]    | --------- associated function in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 48 |     pub fn deserialize(buffer: &mut &[u8]) -> Option<Box<Node>> {
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `load_tree_and_text_from_file` is never used
[INFO] [stdout]    --> src/lib.rs:180:4
[INFO] [stdout]     |
[INFO] [stdout] 180 | fn load_tree_and_text_from_file(file_name: &str) -> Result<(Option<Box<Node>>, String)> {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.31s
[INFO] running `Command { std: "docker" "inspect" "fc3c145acc59a3bfd0c274ee36d16406e4c3c5e5733d2eb131d5f48bf509fa55", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc3c145acc59a3bfd0c274ee36d16406e4c3c5e5733d2eb131d5f48bf509fa55", kill_on_drop: false }`
[INFO] [stdout] fc3c145acc59a3bfd0c274ee36d16406e4c3c5e5733d2eb131d5f48bf509fa55
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9d15df8960a33345431fa0899df310a32a08b05e5ff50a031ae9496c5b6a3d7a
[INFO] running `Command { std: "docker" "start" "-a" "9d15df8960a33345431fa0899df310a32a08b05e5ff50a031ae9496c5b6a3d7a", kill_on_drop: false }`
[INFO] [stdout] warning: unused variable: `codes`
[INFO] [stdout]    --> src/lib.rs:107:10
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_codes`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]    --> src/lib.rs:107:18
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |                  ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> src/lib.rs:156:12
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]     = help: consider replacing the `if let` with a `let`
[INFO] [stdout]     = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iscorrect`
[INFO] [stdout]    --> src/lib.rs:156:16
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |                ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iscorrect`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file_name`
[INFO] [stdout]    --> src/lib.rs:126:28
[INFO] [stdout]     |
[INFO] [stdout] 126 | pub fn encode(input: &str, file_name: String) -> i64 {
[INFO] [stdout]     |                            ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_file_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `deserialize` is never used
[INFO] [stdout]   --> src/lib.rs:48:12
[INFO] [stdout]    |
[INFO] [stdout] 15 | impl Node{
[INFO] [stdout]    | --------- associated function in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 48 |     pub fn deserialize(buffer: &mut &[u8]) -> Option<Box<Node>> {
[INFO] [stdout]    |            ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `load_tree_and_text_from_file` is never used
[INFO] [stdout]    --> src/lib.rs:180:4
[INFO] [stdout]     |
[INFO] [stdout] 180 | fn load_tree_and_text_from_file(file_name: &str) -> Result<(Option<Box<Node>>, String)> {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling huffman_coder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `codes`
[INFO] [stdout]    --> src/lib.rs:107:10
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_codes`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `chars`
[INFO] [stdout]    --> src/lib.rs:107:18
[INFO] [stdout]     |
[INFO] [stdout] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stdout]     |                  ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: irrefutable `if let` pattern
[INFO] [stdout]    --> src/lib.rs:156:12
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stdout]     = help: consider replacing the `if let` with a `let`
[INFO] [stdout]     = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `iscorrect`
[INFO] [stdout]    --> src/lib.rs:156:16
[INFO] [stdout]     |
[INFO] [stdout] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stdout]     |                ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iscorrect`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `file_name`
[INFO] [stdout]    --> src/lib.rs:126:28
[INFO] [stdout]     |
[INFO] [stdout] 126 | pub fn encode(input: &str, file_name: String) -> i64 {
[INFO] [stdout]     |                            ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_file_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.51s
[INFO] running `Command { std: "docker" "inspect" "9d15df8960a33345431fa0899df310a32a08b05e5ff50a031ae9496c5b6a3d7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9d15df8960a33345431fa0899df310a32a08b05e5ff50a031ae9496c5b6a3d7a", kill_on_drop: false }`
[INFO] [stdout] 9d15df8960a33345431fa0899df310a32a08b05e5ff50a031ae9496c5b6a3d7a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 12e3aa13d3cd9859e04e07b70149fc67beca325eb3f8dc578a063a18cdae2544
[INFO] running `Command { std: "docker" "start" "-a" "12e3aa13d3cd9859e04e07b70149fc67beca325eb3f8dc578a063a18cdae2544", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `codes`
[INFO] [stderr]    --> src/lib.rs:107:10
[INFO] [stderr]     |
[INFO] [stderr] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stderr]     |          ^^^^^ help: if this is intentional, prefix it with an underscore: `_codes`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `chars`
[INFO] [stderr]    --> src/lib.rs:107:18
[INFO] [stderr]     |
[INFO] [stderr] 107 |     let (codes , chars): (Vec<String>, Vec<char>);
[INFO] [stderr]     |                  ^^^^^ help: if this is intentional, prefix it with an underscore: `_chars`
[INFO] [stderr] 
[INFO] [stderr] warning: irrefutable `if let` pattern
[INFO] [stderr]    --> src/lib.rs:156:12
[INFO] [stderr]     |
[INFO] [stderr] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stderr]     |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: this pattern will always match, so the `if let` is useless
[INFO] [stderr]     = help: consider replacing the `if let` with a `let`
[INFO] [stderr]     = note: `#[warn(irrefutable_let_patterns)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `iscorrect`
[INFO] [stderr]    --> src/lib.rs:156:16
[INFO] [stderr]     |
[INFO] [stderr] 156 |         if let iscorrect = save_file(&main_node, result, "output.bin".to_string().as_str()){
[INFO] [stderr]     |                ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_iscorrect`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `file_name`
[INFO] [stderr]    --> src/lib.rs:126:28
[INFO] [stderr]     |
[INFO] [stderr] 126 | pub fn encode(input: &str, file_name: String) -> i64 {
[INFO] [stderr]     |                            ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_file_name`
[INFO] [stderr] 
[INFO] [stderr] warning: associated function `deserialize` is never used
[INFO] [stderr]   --> src/lib.rs:48:12
[INFO] [stderr]    |
[INFO] [stderr] 15 | impl Node{
[INFO] [stderr]    | --------- associated function in this implementation
[INFO] [stderr] ...
[INFO] [stderr] 48 |     pub fn deserialize(buffer: &mut &[u8]) -> Option<Box<Node>> {
[INFO] [stderr]    |            ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: function `load_tree_and_text_from_file` is never used
[INFO] [stderr]    --> src/lib.rs:180:4
[INFO] [stderr]     |
[INFO] [stderr] 180 | fn load_tree_and_text_from_file(file_name: &str) -> Result<(Option<Box<Node>>, String)> {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `huffman_coder` (lib) generated 7 warnings
[INFO] [stderr] warning: `huffman_coder` (lib test) generated 5 warnings (5 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/huffman_coder-aea54f85de7bca77)
[INFO] [stdout] 
[INFO] [stdout] running 3 tests
[INFO] [stdout] test tests::test_encode ... ok
[INFO] [stdout] test tests::it_works ... ok
[INFO] [stdout] test tests::test_save_and_load_tree ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- tests::test_save_and_load_tree stdout ----
[INFO] [stdout] 
[INFO] [stdout] thread 'tests::test_save_and_load_tree' (18) panicked at src/lib.rs:233:56:
[INFO] [stdout] called `Result::unwrap()` on an `Err` value: Os { code: 30, kind: ReadOnlyFilesystem, message: "Read-only file system" }
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x55b9739f9082 - std::backtrace_rs::backtrace::libunwind::trace::hcab59e1e990fdc24
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stdout]    1:     0x55b9739f9082 - std::backtrace_rs::backtrace::trace_unsynchronized::he24cc57f3d2f47b7
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stdout]    2:     0x55b9739f9082 - std::sys::backtrace::_print_fmt::hf8d65ede198eeb54
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/backtrace.rs:66:9
[INFO] [stdout]    3:     0x55b9739f9082 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h67edf0e4d33c343c
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/backtrace.rs:39:26
[INFO] [stdout]    4:     0x55b973a0923f - core::fmt::rt::Argument::fmt::hef94184842aeafdd
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/fmt/rt.rs:173:76
[INFO] [stdout]    5:     0x55b973a0923f - core::fmt::write::hcf0c66b48a8fa606
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/fmt/mod.rs:1468:25
[INFO] [stdout]    6:     0x55b9739c65f1 - std::io::default_write_fmt::h69967ac0ba93195f
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/io/mod.rs:639:11
[INFO] [stdout]    7:     0x55b9739c65f1 - std::io::Write::write_fmt::h8db9396209deaa1c
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/io/mod.rs:1954:13
[INFO] [stdout]    8:     0x55b9739d2652 - std::sys::backtrace::BacktraceLock::print::h07e5435aa717b414
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/backtrace.rs:42:9
[INFO] [stdout]    9:     0x55b9739d719f - std::panicking::default_hook::{{closure}}::h91001850288db5f7
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:301:27
[INFO] [stdout]   10:     0x55b9739d7031 - std::panicking::default_hook::h2346dbb704ef5512
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:325:9
[INFO] [stdout]   11:     0x55b973997bfe - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h18383b2e29377420
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/alloc/src/boxed.rs:1999:9
[INFO] [stdout]   12:     0x55b973997bfe - test::test_main_with_exit_callback::{{closure}}::h272d7ef99aef06dc
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:145:21
[INFO] [stdout]   13:     0x55b9739d785f - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h6dba6e441651a0d1
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/alloc/src/boxed.rs:1999:9
[INFO] [stdout]   14:     0x55b9739d785f - std::panicking::panic_with_hook::hd2b063a6090d23a4
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:842:13
[INFO] [stdout]   15:     0x55b9739d76ba - std::panicking::panic_handler::{{closure}}::he666d95f139a333e
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:707:13
[INFO] [stdout]   16:     0x55b9739d2789 - std::sys::backtrace::__rust_end_short_backtrace::h631ad224854ebee5
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/backtrace.rs:174:18
[INFO] [stdout]   17:     0x55b9739baacd - __rustc[1d67440d6e82e4f]::rust_begin_unwind
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:698:5
[INFO] [stdout]   18:     0x55b973a10c90 - core::panicking::panic_fmt::h420ddb7fd73daf53
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/panicking.rs:75:14
[INFO] [stdout]   19:     0x55b973a103d6 - core::result::unwrap_failed::hdde076be853d034f
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/result.rs:1855:5
[INFO] [stdout]   20:     0x55b97397269b - core::result::Result<T,E>::unwrap::h6c7216eae5232b3a
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/result.rs:1226:23
[INFO] [stdout]   21:     0x55b97397269b - huffman_coder::tests::test_save_and_load_tree::h7f83f9dc46621a87
[INFO] [stdout]                                at /opt/rustwide/workdir/src/lib.rs:233:56
[INFO] [stdout]   22:     0x55b973972b67 - huffman_coder::tests::test_save_and_load_tree::{{closure}}::hc71593ffe00e0c44
[INFO] [stdout]                                at /opt/rustwide/workdir/src/lib.rs:226:33
[INFO] [stdout]   23:     0x55b97396d056 - core::ops::function::FnOnce::call_once::h403205c9059b916e
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   24:     0x55b9739979bb - core::ops::function::FnOnce::call_once::h70887edf07a630ba
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   25:     0x55b9739979bb - test::__rust_begin_short_backtrace::h27763c4cbbdb8601
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:663:18
[INFO] [stdout]   26:     0x55b9739ad625 - test::run_test_in_process::{{closure}}::h4dc8bc6d5e3924d3
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:686:74
[INFO] [stdout]   27:     0x55b9739ad625 - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h75905e8ffe81974f
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   28:     0x55b9739ad625 - std::panicking::catch_unwind::do_call::h0bc60366ba66eba5
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:590:40
[INFO] [stdout]   29:     0x55b9739ad625 - std::panicking::catch_unwind::hae1ec7bf94407afa
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:553:19
[INFO] [stdout]   30:     0x55b9739ad625 - std::panic::catch_unwind::h0f4ff4773d84d3cd
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panic.rs:359:14
[INFO] [stdout]   31:     0x55b9739ad625 - test::run_test_in_process::h03fbc77ae48b3f10
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:686:27
[INFO] [stdout]   32:     0x55b9739ad625 - test::run_test::{{closure}}::h83476a9c453dc4d3
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:607:43
[INFO] [stdout]   33:     0x55b973983e14 - test::run_test::{{closure}}::h515482ad1e7fe7de
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/test/src/lib.rs:637:41
[INFO] [stdout]   34:     0x55b973983e14 - std::sys::backtrace::__rust_begin_short_backtrace::hed09f6ac5fe9d647
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/backtrace.rs:158:18
[INFO] [stdout]   35:     0x55b9739876da - std::thread::Builder::spawn_unchecked_::{{closure}}::{{closure}}::h988e2cd969319888
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/thread/mod.rs:559:17
[INFO] [stdout]   36:     0x55b9739876da - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::hd70e28dc46ec20be
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/panic/unwind_safe.rs:274:9
[INFO] [stdout]   37:     0x55b9739876da - std::panicking::catch_unwind::do_call::hdc29e11311eb7655
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:590:40
[INFO] [stdout]   38:     0x55b9739876da - std::panicking::catch_unwind::h9e402d6a96fef41c
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panicking.rs:553:19
[INFO] [stdout]   39:     0x55b9739876da - std::panic::catch_unwind::h9213c0c54aec70e0
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/panic.rs:359:14
[INFO] [stdout]   40:     0x55b9739876da - std::thread::Builder::spawn_unchecked_::{{closure}}::h6262965869ed2b87
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/thread/mod.rs:557:30
[INFO] [stdout]   41:     0x55b9739876da - core::ops::function::FnOnce::call_once{{vtable.shim}}::h05c05ed02619e462
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/ops/function.rs:250:5
[INFO] [stdout]   42:     0x55b9739cd8ef - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h2044e71c41d3958a
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/alloc/src/boxed.rs:1985:9
[INFO] [stdout]   43:     0x55b9739cd8ef - std::sys::thread::unix::Thread::new::thread_start::hf277835320aa8e5a
[INFO] [stdout]                                at /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/std/src/sys/thread/unix.rs:126:17
[INFO] [stdout]   44:     0x713088331aa4 - <unknown>
[INFO] [stdout]   45:     0x7130883bea34 - clone
[INFO] [stdout]   46:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     tests::test_save_and_load_tree
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 2 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.08s
[INFO] [stdout] 
[INFO] [stderr] error: test failed, to rerun pass `--lib`
[INFO] running `Command { std: "docker" "inspect" "12e3aa13d3cd9859e04e07b70149fc67beca325eb3f8dc578a063a18cdae2544", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12e3aa13d3cd9859e04e07b70149fc67beca325eb3f8dc578a063a18cdae2544", kill_on_drop: false }`
[INFO] [stdout] 12e3aa13d3cd9859e04e07b70149fc67beca325eb3f8dc578a063a18cdae2544
