[INFO] cloning repository https://github.com/actualchao/rust-learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/actualchao/rust-learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Factualchao%2Frust-learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Factualchao%2Frust-learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9fd81a4b2ee777520779c7a699fe9a7e44afadcc
[INFO] building actualchao/rust-learn 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%2Factualchao%2Frust-learn" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/actualchao/rust-learn 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/actualchao/rust-learn
[INFO] finished tweaking git repo https://github.com/actualchao/rust-learn
[INFO] tweaked toml for git repo https://github.com/actualchao/rust-learn written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/actualchao/rust-learn 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 3133a3b78ba219d39867a3e9ebd5a76e1b0a136c1b6819c6328be2eaa15ecdc1
[INFO] running `Command { std: "docker" "start" "-a" "3133a3b78ba219d39867a3e9ebd5a76e1b0a136c1b6819c6328be2eaa15ecdc1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3133a3b78ba219d39867a3e9ebd5a76e1b0a136c1b6819c6328be2eaa15ecdc1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3133a3b78ba219d39867a3e9ebd5a76e1b0a136c1b6819c6328be2eaa15ecdc1", kill_on_drop: false }`
[INFO] [stdout] 3133a3b78ba219d39867a3e9ebd5a76e1b0a136c1b6819c6328be2eaa15ecdc1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 42a3c314cb6a17e389c396198b1fe3148f48bd8aea4ec48b916d817fbf23db9a
[INFO] running `Command { std: "docker" "start" "-a" "42a3c314cb6a17e389c396198b1fe3148f48bd8aea4ec48b916d817fbf23db9a", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling getrandom v0.2.6
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling hello_cargo v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/primitives/tuples.rs:19:10
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (a, b) = test_tuples;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/primitives/tuples.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (a, b) = test_tuples;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.46s
[INFO] running `Command { std: "docker" "inspect" "42a3c314cb6a17e389c396198b1fe3148f48bd8aea4ec48b916d817fbf23db9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42a3c314cb6a17e389c396198b1fe3148f48bd8aea4ec48b916d817fbf23db9a", kill_on_drop: false }`
[INFO] [stdout] 42a3c314cb6a17e389c396198b1fe3148f48bd8aea4ec48b916d817fbf23db9a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] a0c24a2deb077f6af519240276b8c9122b56d5c0c419a8e0a229ab474e1d9b19
[INFO] running `Command { std: "docker" "start" "-a" "a0c24a2deb077f6af519240276b8c9122b56d5c0c419a8e0a229ab474e1d9b19", kill_on_drop: false }`
[INFO] [stderr]    Compiling hello_cargo v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]   --> src/primitives/tuples.rs:19:10
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (a, b) = test_tuples;
[INFO] [stdout]    |          ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/primitives/tuples.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let (a, b) = test_tuples;
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.21s
[INFO] running `Command { std: "docker" "inspect" "a0c24a2deb077f6af519240276b8c9122b56d5c0c419a8e0a229ab474e1d9b19", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a0c24a2deb077f6af519240276b8c9122b56d5c0c419a8e0a229ab474e1d9b19", kill_on_drop: false }`
[INFO] [stdout] a0c24a2deb077f6af519240276b8c9122b56d5c0c419a8e0a229ab474e1d9b19