[INFO] cloning repository https://github.com/Saber-Kurama/rustlings-answer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Saber-Kurama/rustlings-answer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSaber-Kurama%2Frustlings-answer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSaber-Kurama%2Frustlings-answer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 195683c61a74dc75ed110d77f37a58bf13b7b321
[INFO] checking Saber-Kurama/rustlings-answer against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSaber-Kurama%2Frustlings-answer" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Saber-Kurama/rustlings-answer 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/Saber-Kurama/rustlings-answer
[INFO] finished tweaking git repo https://github.com/Saber-Kurama/rustlings-answer
[INFO] tweaked toml for git repo https://github.com/Saber-Kurama/rustlings-answer written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Saber-Kurama/rustlings-answer 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]  Downloading crates ...
[INFO] [stderr]   Downloaded console v0.7.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] 97a77c7ff559c0e61cc721469602a65cb4844daaff27f585546ed9e39b692054
[INFO] running `Command { std: "docker" "start" "-a" "97a77c7ff559c0e61cc721469602a65cb4844daaff27f585546ed9e39b692054", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "97a77c7ff559c0e61cc721469602a65cb4844daaff27f585546ed9e39b692054", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97a77c7ff559c0e61cc721469602a65cb4844daaff27f585546ed9e39b692054", kill_on_drop: false }`
[INFO] [stdout] 97a77c7ff559c0e61cc721469602a65cb4844daaff27f585546ed9e39b692054
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] a7a2c135ddabde5e124861accd836ba2ddcbfec8027573798f83434bde23b71e
[INFO] running `Command { std: "docker" "start" "-a" "a7a2c135ddabde5e124861accd836ba2ddcbfec8027573798f83434bde23b71e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking termios v0.3.3
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking indicatif v0.10.3
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]     Checking argh v0.1.5
[INFO] [stderr]     Checking serde v1.0.129
[INFO] [stderr]     Checking serde_json v1.0.66
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v4.6.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 19.47s
[INFO] running `Command { std: "docker" "inspect" "a7a2c135ddabde5e124861accd836ba2ddcbfec8027573798f83434bde23b71e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7a2c135ddabde5e124861accd836ba2ddcbfec8027573798f83434bde23b71e", kill_on_drop: false }`
[INFO] [stdout] a7a2c135ddabde5e124861accd836ba2ddcbfec8027573798f83434bde23b71e
[INFO] checking Saber-Kurama/rustlings-answer against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSaber-Kurama%2Frustlings-answer" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Saber-Kurama/rustlings-answer 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/Saber-Kurama/rustlings-answer
[INFO] finished tweaking git repo https://github.com/Saber-Kurama/rustlings-answer
[INFO] tweaked toml for git repo https://github.com/Saber-Kurama/rustlings-answer written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Saber-Kurama/rustlings-answer 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-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] 7e3f3679bdd0dfe2ae0209c6d4922df99ee7fdd58aa10c01cdccbf1a52fe4d7e
[INFO] running `Command { std: "docker" "start" "-a" "7e3f3679bdd0dfe2ae0209c6d4922df99ee7fdd58aa10c01cdccbf1a52fe4d7e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7e3f3679bdd0dfe2ae0209c6d4922df99ee7fdd58aa10c01cdccbf1a52fe4d7e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e3f3679bdd0dfe2ae0209c6d4922df99ee7fdd58aa10c01cdccbf1a52fe4d7e", kill_on_drop: false }`
[INFO] [stdout] 7e3f3679bdd0dfe2ae0209c6d4922df99ee7fdd58aa10c01cdccbf1a52fe4d7e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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] 6701fbd7542bb3b10afcf8dc6c91bc9845be26da624bf0c53830d8593f87f336
[INFO] running `Command { std: "docker" "start" "-a" "6701fbd7542bb3b10afcf8dc6c91bc9845be26da624bf0c53830d8593f87f336", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.100
[INFO] [stderr]    Compiling syn v1.0.75
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking termios v0.3.3
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking predicates v1.0.8
[INFO] [stderr]     Checking indicatif v0.10.3
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking notify v4.0.17
[INFO] [stderr]    Compiling serde_derive v1.0.129
[INFO] [stderr]    Compiling argh_derive v0.1.5
[INFO] [stderr]     Checking argh v0.1.5
[INFO] [stderr]     Checking serde v1.0.129
[INFO] [stderr]     Checking serde_json v1.0.66
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v4.6.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 18.98s
[INFO] running `Command { std: "docker" "inspect" "6701fbd7542bb3b10afcf8dc6c91bc9845be26da624bf0c53830d8593f87f336", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6701fbd7542bb3b10afcf8dc6c91bc9845be26da624bf0c53830d8593f87f336", kill_on_drop: false }`
[INFO] [stdout] 6701fbd7542bb3b10afcf8dc6c91bc9845be26da624bf0c53830d8593f87f336