[INFO] cloning repository https://github.com/arthur-teixeira/huffman-coding
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/arthur-teixeira/huffman-coding" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farthur-teixeira%2Fhuffman-coding", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farthur-teixeira%2Fhuffman-coding'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 85c8b1e3c575cb553b4802f30c62ae818cd4597a
[INFO] building arthur-teixeira/huffman-coding against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farthur-teixeira%2Fhuffman-coding" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/arthur-teixeira/huffman-coding on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/arthur-teixeira/huffman-coding
[INFO] finished tweaking git repo https://github.com/arthur-teixeira/huffman-coding
[INFO] tweaked toml for git repo https://github.com/arthur-teixeira/huffman-coding written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/arthur-teixeira/huffman-coding 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d1b25b58b71210a5cb21e2ad6c77a0c9bb6133ecc55ef457499c1351e640d53a
[INFO] running `Command { std: "docker" "start" "-a" "d1b25b58b71210a5cb21e2ad6c77a0c9bb6133ecc55ef457499c1351e640d53a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d1b25b58b71210a5cb21e2ad6c77a0c9bb6133ecc55ef457499c1351e640d53a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d1b25b58b71210a5cb21e2ad6c77a0c9bb6133ecc55ef457499c1351e640d53a", kill_on_drop: false }`
[INFO] [stdout] d1b25b58b71210a5cb21e2ad6c77a0c9bb6133ecc55ef457499c1351e640d53a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8bf162828d4af89d2fa3d5131fe621c20237c474451af0204a4ec0f725aee18e
[INFO] running `Command { std: "docker" "start" "-a" "8bf162828d4af89d2fa3d5131fe621c20237c474451af0204a4ec0f725aee18e", kill_on_drop: false }`
[INFO] [stderr]    Compiling huffman-encoding v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `output_path`
[INFO] [stdout]    --> src/main.rs:316:39
[INFO] [stdout]     |
[INFO] [stdout] 316 | fn do_decompression(input_path: &str, output_path: &str) -> Result<(), Box<dyn Error>> {
[INFO] [stdout]     |                                       ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_output_path`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `at` is never used
[INFO] [stdout]    --> src/main.rs:196:8
[INFO] [stdout]     |
[INFO] [stdout] 161 | impl Bitfield {
[INFO] [stdout]     | ------------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 196 |     fn at(&self, pos: usize) -> Option<u8> {
[INFO] [stdout]     |        ^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `decompress` is never used
[INFO] [stdout]    --> src/main.rs:253:4
[INFO] [stdout]     |
[INFO] [stdout] 253 | fn decompress(compressed: &mut Bitfield, tree: &HuffmanTree) -> String {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `decompress_recur` is never used
[INFO] [stdout]    --> src/main.rs:262:4
[INFO] [stdout]     |
[INFO] [stdout] 262 | fn decompress_recur(
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "8bf162828d4af89d2fa3d5131fe621c20237c474451af0204a4ec0f725aee18e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bf162828d4af89d2fa3d5131fe621c20237c474451af0204a4ec0f725aee18e", kill_on_drop: false }`
[INFO] [stdout] 8bf162828d4af89d2fa3d5131fe621c20237c474451af0204a4ec0f725aee18e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bef11779a278549b7805e31872e6ca6e9f8dae59407b0837c67543669024a43e
[INFO] running `Command { std: "docker" "start" "-a" "bef11779a278549b7805e31872e6ca6e9f8dae59407b0837c67543669024a43e", kill_on_drop: false }`
[INFO] [stderr]    Compiling huffman-encoding v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `output_path`
[INFO] [stdout]    --> src/main.rs:316:39
[INFO] [stdout]     |
[INFO] [stdout] 316 | fn do_decompression(input_path: &str, output_path: &str) -> Result<(), Box<dyn Error>> {
[INFO] [stdout]     |                                       ^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_output_path`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `get_compressed` is never used
[INFO] [stdout]    --> src/main.rs:363:8
[INFO] [stdout]     |
[INFO] [stdout] 363 |     fn get_compressed(sut: &str) -> crate::Bitfield {
[INFO] [stdout]     |        ^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.22s
[INFO] running `Command { std: "docker" "inspect" "bef11779a278549b7805e31872e6ca6e9f8dae59407b0837c67543669024a43e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bef11779a278549b7805e31872e6ca6e9f8dae59407b0837c67543669024a43e", kill_on_drop: false }`
[INFO] [stdout] bef11779a278549b7805e31872e6ca6e9f8dae59407b0837c67543669024a43e