[INFO] cloning repository https://github.com/hemantkgupta/prog-rust-2nd-ws
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hemantkgupta/prog-rust-2nd-ws" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhemantkgupta%2Fprog-rust-2nd-ws", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhemantkgupta%2Fprog-rust-2nd-ws'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7e7ada8d537a54938271437fab1cb3e3a24f58da
[INFO] checking hemantkgupta/prog-rust-2nd-ws against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhemantkgupta%2Fprog-rust-2nd-ws" "/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/hemantkgupta/prog-rust-2nd-ws on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/hemantkgupta/prog-rust-2nd-ws
[INFO] finished tweaking git repo https://github.com/hemantkgupta/prog-rust-2nd-ws
[INFO] tweaked toml for git repo https://github.com/hemantkgupta/prog-rust-2nd-ws written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/hemantkgupta/prog-rust-2nd-ws 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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded libnghttp2-sys v0.1.8+1.55.1
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8acd275a61b695e04c6daae7a29eef59c7c70041d10c61469de7e9f3fac08c67
[INFO] running `Command { std: "docker" "start" "-a" "8acd275a61b695e04c6daae7a29eef59c7c70041d10c61469de7e9f3fac08c67", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8acd275a61b695e04c6daae7a29eef59c7c70041d10c61469de7e9f3fac08c67", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8acd275a61b695e04c6daae7a29eef59c7c70041d10c61469de7e9f3fac08c67", kill_on_drop: false }`
[INFO] [stdout] 8acd275a61b695e04c6daae7a29eef59c7c70041d10c61469de7e9f3fac08c67
[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" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8ab6c16422a7e98961243c5c03f371881ba873a2124e60d73fed45823c3132ae
[INFO] running `Command { std: "docker" "start" "-a" "8ab6c16422a7e98961243c5c03f371881ba873a2124e60d73fed45823c3132ae", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.150
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[INFO] [stderr]     Checking ch10_enums_and_patterns v0.1.0 (/opt/rustwide/workdir/ch10_enums_and_patterns)
[INFO] [stdout] warning: the item `integration_testing` is imported redundantly
[INFO] [stdout]  --> integration_testing/tests/integration_tests.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use integration_testing;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^ the item `integration_testing` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
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[INFO] [stderr]    Compiling openssl-macros v0.1.1
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[INFO] [stderr]     Checking tokio-util v0.7.10
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[INFO] [stderr]     Checking futures v0.3.29
[INFO] [stderr]     Checking ch20_async v0.1.0 (/opt/rustwide/workdir/ch20_async)
[INFO] [stdout] warning: the item `Future` is imported redundantly
[INFO] [stdout]   --> ch20_async/src/async4.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 2  |     prelude::*, 
[INFO] [stdout]    |     ---------- the item `Future` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 12 |     future::Future,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Future` is imported redundantly
[INFO] [stdout]   --> ch20_async/src/async4.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 2  |     prelude::*, 
[INFO] [stdout]    |     ---------- the item `Future` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 12 |     future::Future,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
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[INFO] [stderr]     Checking hyper-tls v0.5.0
[INFO] [stderr]     Checking reqwest v0.11.22
[INFO] [stderr]     Checking ch18_io v0.1.0 (/opt/rustwide/workdir/ch18_io)
[INFO] [stdout] warning: the item `reqwest` is imported redundantly
[INFO] [stdout]  --> ch18_io/src/networking2.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use reqwest;
[INFO] [stdout]   |     ^^^^^^^ the item `reqwest` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `reqwest` is imported redundantly
[INFO] [stdout]  --> ch18_io/src/networking2.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use reqwest;
[INFO] [stdout]   |     ^^^^^^^ the item `reqwest` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 14.25s
[INFO] running `Command { std: "docker" "inspect" "8ab6c16422a7e98961243c5c03f371881ba873a2124e60d73fed45823c3132ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ab6c16422a7e98961243c5c03f371881ba873a2124e60d73fed45823c3132ae", kill_on_drop: false }`
[INFO] [stdout] 8ab6c16422a7e98961243c5c03f371881ba873a2124e60d73fed45823c3132ae