[INFO] cloning repository https://github.com/LearningOS/rust-rustlings-hank20010209
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/LearningOS/rust-rustlings-hank20010209" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Frust-rustlings-hank20010209", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Frust-rustlings-hank20010209'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1c4d6a0b5c8bff2bbb7a3719796ae85043b8d4df
[INFO] checking LearningOS/rust-rustlings-hank20010209 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Frust-rustlings-hank20010209" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/LearningOS/rust-rustlings-hank20010209 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 git repo https://github.com/LearningOS/rust-rustlings-hank20010209
[INFO] finished tweaking git repo https://github.com/LearningOS/rust-rustlings-hank20010209
[INFO] tweaked toml for git repo https://github.com/LearningOS/rust-rustlings-hank20010209 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/rust-rustlings-hank20010209 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 635592406c876ad69d21d8405f0eba32b1a14d4dc0d13843d370854db3ca403a
[INFO] running `Command { std: "docker" "start" "-a" "635592406c876ad69d21d8405f0eba32b1a14d4dc0d13843d370854db3ca403a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "635592406c876ad69d21d8405f0eba32b1a14d4dc0d13843d370854db3ca403a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "635592406c876ad69d21d8405f0eba32b1a14d4dc0d13843d370854db3ca403a", kill_on_drop: false }`
[INFO] [stdout] 635592406c876ad69d21d8405f0eba32b1a14d4dc0d13843d370854db3ca403a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] ef1a241f178bf083f8ed6b46a14f26bd2fdb3cc4875420238fbf68f6fe10cbb5
[INFO] running `Command { std: "docker" "start" "-a" "ef1a241f178bf083f8ed6b46a14f26bd2fdb3cc4875420238fbf68f6fe10cbb5", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.137
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling serde v1.0.129
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]    Compiling parking_lot_core v0.9.4
[INFO] [stderr]     Checking slab v0.4.4
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking smallvec v1.10.0
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling tokio v1.21.2
[INFO] [stderr]    Compiling argh_shared v0.1.5
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking predicates-core v1.0.2
[INFO] [stderr]     Checking once_cell v1.10.0
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking walkdir v2.3.2
[INFO] [stderr]     Checking num_cpus v1.13.1
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking mio v0.8.5
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking socket2 v0.4.7
[INFO] [stderr]     Checking pin-project-lite v0.2.9
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking bytes v1.2.1
[INFO] [stderr]     Checking predicates-tree v1.0.3
[INFO] [stderr]     Checking home v0.5.3
[INFO] [stderr]     Checking glob v0.3.0
[INFO] [stderr]     Checking regex v1.5.5
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stderr]     Checking console v0.15.0
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking indicatif v0.16.2
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]    Compiling tokio-macros v1.8.0
[INFO] [stderr]     Checking argh v0.1.5
[INFO] [stderr]     Checking toml v0.5.9
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking rustlings v5.2.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 22.93s
[INFO] running `Command { std: "docker" "inspect" "ef1a241f178bf083f8ed6b46a14f26bd2fdb3cc4875420238fbf68f6fe10cbb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef1a241f178bf083f8ed6b46a14f26bd2fdb3cc4875420238fbf68f6fe10cbb5", kill_on_drop: false }`
[INFO] [stdout] ef1a241f178bf083f8ed6b46a14f26bd2fdb3cc4875420238fbf68f6fe10cbb5
[INFO] checking LearningOS/rust-rustlings-hank20010209 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLearningOS%2Frust-rustlings-hank20010209" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/LearningOS/rust-rustlings-hank20010209 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 git repo https://github.com/LearningOS/rust-rustlings-hank20010209
[INFO] finished tweaking git repo https://github.com/LearningOS/rust-rustlings-hank20010209
[INFO] tweaked toml for git repo https://github.com/LearningOS/rust-rustlings-hank20010209 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/LearningOS/rust-rustlings-hank20010209 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-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] d86d4952f26ac81d903b9191c5483358a925bd0c6c140264a07d928f2a6a9489
[INFO] running `Command { std: "docker" "start" "-a" "d86d4952f26ac81d903b9191c5483358a925bd0c6c140264a07d928f2a6a9489", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d86d4952f26ac81d903b9191c5483358a925bd0c6c140264a07d928f2a6a9489", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d86d4952f26ac81d903b9191c5483358a925bd0c6c140264a07d928f2a6a9489", kill_on_drop: false }`
[INFO] [stdout] d86d4952f26ac81d903b9191c5483358a925bd0c6c140264a07d928f2a6a9489
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 86e19073066d8161e8641a21b21a12cb885c76f3d011496bf074a342fbe4d927
[INFO] running `Command { std: "docker" "start" "-a" "86e19073066d8161e8641a21b21a12cb885c76f3d011496bf074a342fbe4d927", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.137
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling serde v1.0.129
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling serde_json v1.0.81
[INFO] [stderr]    Compiling parking_lot_core v0.9.4
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]     Checking itoa v1.0.2
[INFO] [stderr]     Checking smallvec v1.10.0
[INFO] [stderr]     Checking slab v0.4.4
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling tokio v1.21.2
[INFO] [stderr]    Compiling argh_shared v0.1.5
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking once_cell v1.10.0
[INFO] [stderr]     Checking predicates-core v1.0.2
[INFO] [stderr]     Checking parking_lot v0.12.1
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking walkdir v2.3.2
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking socket2 v0.4.7
[INFO] [stderr]     Checking mio v0.8.5
[INFO] [stderr]     Checking num_cpus v1.13.1
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking pin-project-lite v0.2.9
[INFO] [stderr]     Checking bytes v1.2.1
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking glob v0.3.0
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking home v0.5.3
[INFO] [stderr]     Checking predicates-tree v1.0.3
[INFO] [stderr]     Checking regex v1.5.5
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stderr]     Checking console v0.15.0
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking indicatif v0.16.2
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]    Compiling tokio-macros v1.8.0
[INFO] [stderr]     Checking argh v0.1.5
[INFO] [stderr]     Checking toml v0.5.9
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Checking rustlings v5.2.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 22.04s
[INFO] running `Command { std: "docker" "inspect" "86e19073066d8161e8641a21b21a12cb885c76f3d011496bf074a342fbe4d927", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "86e19073066d8161e8641a21b21a12cb885c76f3d011496bf074a342fbe4d927", kill_on_drop: false }`
[INFO] [stdout] 86e19073066d8161e8641a21b21a12cb885c76f3d011496bf074a342fbe4d927