[INFO] cloning repository https://github.com/ryankav/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ryankav/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryankav%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryankav%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2a3b11ce63bf1c906efd8a884626ed951e39f0b0
[INFO] checking ryankav/rustlings against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryankav%2Frustlings" "/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/ryankav/rustlings 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/ryankav/rustlings
[INFO] finished tweaking git repo https://github.com/ryankav/rustlings
[INFO] tweaked toml for git repo https://github.com/ryankav/rustlings written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/ryankav/rustlings 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-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 191c56fcf95cb2b4bd4c145c8c1e47928625fdffb33519b52554be0b8b62a6e3
[INFO] running `Command { std: "docker" "start" "-a" "191c56fcf95cb2b4bd4c145c8c1e47928625fdffb33519b52554be0b8b62a6e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "191c56fcf95cb2b4bd4c145c8c1e47928625fdffb33519b52554be0b8b62a6e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "191c56fcf95cb2b4bd4c145c8c1e47928625fdffb33519b52554be0b8b62a6e3", kill_on_drop: false }`
[INFO] [stdout] 191c56fcf95cb2b4bd4c145c8c1e47928625fdffb33519b52554be0b8b62a6e3
[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" "-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] 3704d1ba364f5e374733fdaf01ad3faf0a73c6307740850f498ac7880557d1a2
[INFO] running `Command { std: "docker" "start" "-a" "3704d1ba364f5e374733fdaf01ad3faf0a73c6307740850f498ac7880557d1a2", 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 itoa v0.4.8
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking termios v0.3.3
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking filetime v0.2.15
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking console v0.7.7
[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 v4.5.0 (/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 13.85s
[INFO] running `Command { std: "docker" "inspect" "3704d1ba364f5e374733fdaf01ad3faf0a73c6307740850f498ac7880557d1a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3704d1ba364f5e374733fdaf01ad3faf0a73c6307740850f498ac7880557d1a2", kill_on_drop: false }`
[INFO] [stdout] 3704d1ba364f5e374733fdaf01ad3faf0a73c6307740850f498ac7880557d1a2