[INFO] fetching crate bulls-and-cows 1.0.21...
[INFO] checking bulls-and-cows-1.0.21 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] extracting crate bulls-and-cows 1.0.21 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate bulls-and-cows 1.0.21 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate bulls-and-cows 1.0.21
[INFO] finished tweaking crates.io crate bulls-and-cows 1.0.21
[INFO] tweaked toml for crates.io crate bulls-and-cows 1.0.21 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate crates.io crate bulls-and-cows 1.0.21 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded random-number v0.1.8
[INFO] [stderr]   Downloaded random-pick v1.2.16
[INFO] [stderr]   Downloaded random-number-macro-impl v0.1.7
[INFO] [stderr]   Downloaded debug-helper v0.3.13
[INFO] [stderr]   Downloaded permutohedron v0.2.4
[INFO] [stderr]   Downloaded regex v1.9.5
[INFO] [stderr]   Downloaded aho-corasick v1.0.5
[INFO] [stderr]   Downloaded syn v2.0.31
[INFO] [stderr]   Downloaded regex-automata v0.3.8
[INFO] [stderr]   Downloaded regex-syntax v0.7.5
[INFO] [stderr]   Downloaded memchr v2.6.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f2ff08556e367d8a552b4783ea752f367873b68df1757c5480e96f9af0b9b567
[INFO] running `Command { std: "docker" "start" "-a" "f2ff08556e367d8a552b4783ea752f367873b68df1757c5480e96f9af0b9b567", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f2ff08556e367d8a552b4783ea752f367873b68df1757c5480e96f9af0b9b567", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f2ff08556e367d8a552b4783ea752f367873b68df1757c5480e96f9af0b9b567", kill_on_drop: false }`
[INFO] [stdout] f2ff08556e367d8a552b4783ea752f367873b68df1757c5480e96f9af0b9b567
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e8692710887464cbb742dae3af2f6ac753dcf87bb0706951894b8d0caac241c9
[INFO] running `Command { std: "docker" "start" "-a" "e8692710887464cbb742dae3af2f6ac753dcf87bb0706951894b8d0caac241c9", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.147
[INFO] [stderr]    Compiling proc-macro2 v1.0.66
[INFO] [stderr]    Compiling proc-macro-hack v0.5.20+deprecated
[INFO] [stderr]     Checking memchr v2.6.3
[INFO] [stderr]     Checking regex-syntax v0.7.5
[INFO] [stderr]     Checking debug-helper v0.3.13
[INFO] [stderr]     Checking permutohedron v0.2.4
[INFO] [stderr]     Checking aho-corasick v1.0.5
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]    Compiling syn v2.0.31
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking regex-automata v0.3.8
[INFO] [stderr]     Checking regex v1.9.5
[INFO] [stderr]    Compiling random-number-macro-impl v0.1.7
[INFO] [stderr]     Checking random-number v0.1.8
[INFO] [stderr]     Checking random-pick v1.2.16
[INFO] [stderr]     Checking bulls-and-cows v1.0.21 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `random_pick` is imported redundantly
[INFO] [stdout]  --> src/play/players/computer.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use random_pick;
[INFO] [stdout]   |     ^^^^^^^^^^^ the item `random_pick` 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 `random_pick` is imported redundantly
[INFO] [stdout]  --> src/play/players/computer.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use random_pick;
[INFO] [stdout]   |     ^^^^^^^^^^^ the item `random_pick` 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 3.19s
[INFO] running `Command { std: "docker" "inspect" "e8692710887464cbb742dae3af2f6ac753dcf87bb0706951894b8d0caac241c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8692710887464cbb742dae3af2f6ac753dcf87bb0706951894b8d0caac241c9", kill_on_drop: false }`
[INFO] [stdout] e8692710887464cbb742dae3af2f6ac753dcf87bb0706951894b8d0caac241c9
[INFO] checking bulls-and-cows-1.0.21 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] extracting crate bulls-and-cows 1.0.21 into /workspace/builds/worker-2-tc2/source
[INFO] validating manifest of crates.io crate bulls-and-cows 1.0.21 on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate bulls-and-cows 1.0.21
[INFO] finished tweaking crates.io crate bulls-and-cows 1.0.21
[INFO] tweaked toml for crates.io crate bulls-and-cows 1.0.21 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate crates.io crate bulls-and-cows 1.0.21 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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 228b1fa7e9cb351f5810821885f354fa00cfb83b63b5cf770fd6ff11eca45e20
[INFO] running `Command { std: "docker" "start" "-a" "228b1fa7e9cb351f5810821885f354fa00cfb83b63b5cf770fd6ff11eca45e20", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "228b1fa7e9cb351f5810821885f354fa00cfb83b63b5cf770fd6ff11eca45e20", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "228b1fa7e9cb351f5810821885f354fa00cfb83b63b5cf770fd6ff11eca45e20", kill_on_drop: false }`
[INFO] [stdout] 228b1fa7e9cb351f5810821885f354fa00cfb83b63b5cf770fd6ff11eca45e20
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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=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" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 77962b0ece83fe2b19f8d0164784c00f6d8591a2e9a3a453f7045a8a80c41a81
[INFO] running `Command { std: "docker" "start" "-a" "77962b0ece83fe2b19f8d0164784c00f6d8591a2e9a3a453f7045a8a80c41a81", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.147
[INFO] [stderr]    Compiling proc-macro2 v1.0.66
[INFO] [stderr]    Compiling proc-macro-hack v0.5.20+deprecated
[INFO] [stderr]     Checking memchr v2.6.3
[INFO] [stderr]     Checking regex-syntax v0.7.5
[INFO] [stderr]     Checking permutohedron v0.2.4
[INFO] [stderr]     Checking debug-helper v0.3.13
[INFO] [stderr]     Checking aho-corasick v1.0.5
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]    Compiling syn v2.0.31
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking regex-automata v0.3.8
[INFO] [stderr]     Checking regex v1.9.5
[INFO] [stderr]    Compiling random-number-macro-impl v0.1.7
[INFO] [stderr]     Checking random-number v0.1.8
[INFO] [stderr]     Checking random-pick v1.2.16
[INFO] [stderr]     Checking bulls-and-cows v1.0.21 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `random_pick` is imported redundantly
[INFO] [stdout]  --> src/play/players/computer.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use random_pick;
[INFO] [stdout]   |     ^^^^^^^^^^^ the item `random_pick` 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 `random_pick` is imported redundantly
[INFO] [stdout]  --> src/play/players/computer.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use random_pick;
[INFO] [stdout]   |     ^^^^^^^^^^^ the item `random_pick` 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 3.12s
[INFO] running `Command { std: "docker" "inspect" "77962b0ece83fe2b19f8d0164784c00f6d8591a2e9a3a453f7045a8a80c41a81", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "77962b0ece83fe2b19f8d0164784c00f6d8591a2e9a3a453f7045a8a80c41a81", kill_on_drop: false }`
[INFO] [stdout] 77962b0ece83fe2b19f8d0164784c00f6d8591a2e9a3a453f7045a8a80c41a81