[INFO] cloning repository https://github.com/dvlden/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dvlden/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdvlden%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdvlden%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e9a33c2fdca7c628da584c5e7c04d13ce319c400
[INFO] checking dvlden/rustlings against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdvlden%2Frustlings" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dvlden/rustlings on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dvlden/rustlings
[INFO] finished tweaking git repo https://github.com/dvlden/rustlings
[INFO] tweaked toml for git repo https://github.com/dvlden/rustlings written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/dvlden/rustlings already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-9/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ae32b21a2f322630de239ef98241bcc8fe8f52ff7cccc5c1872afd2761223342
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "ae32b21a2f322630de239ef98241bcc8fe8f52ff7cccc5c1872afd2761223342", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ae32b21a2f322630de239ef98241bcc8fe8f52ff7cccc5c1872afd2761223342", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ae32b21a2f322630de239ef98241bcc8fe8f52ff7cccc5c1872afd2761223342", kill_on_drop: false }`
[INFO] [stdout] ae32b21a2f322630de239ef98241bcc8fe8f52ff7cccc5c1872afd2761223342
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 30fbadbbcc8f8ac6c299107f035595b611b99e29438e180628676f3ac84ed48b
[INFO] running `Command { std: "docker" "start" "-a" "30fbadbbcc8f8ac6c299107f035595b611b99e29438e180628676f3ac84ed48b", kill_on_drop: false }`
[INFO] [stderr]     Checking normalize-line-endings v0.3.0
[INFO] [stderr]     Checking lock_api v0.4.1
[INFO] [stderr]     Checking instant v0.1.8
[INFO] [stderr]     Checking float-cmp v0.8.0
[INFO] [stderr]     Checking number_prefix v0.2.8
[INFO] [stderr]     Checking inotify-sys v0.1.4
[INFO] [stderr]     Checking terminal_size v0.1.15
[INFO] [stderr]     Checking termios v0.3.3
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking filetime v0.2.13
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking serde v1.0.117
[INFO] [stderr]     Checking mio-extras v2.0.6
[INFO] [stderr]     Checking parking_lot_core v0.8.0
[INFO] [stderr]     Checking predicates v1.0.5
[INFO] [stderr]     Checking console v0.13.0
[INFO] [stderr]     Checking inotify v0.7.1
[INFO] [stderr]     Checking parking_lot v0.11.0
[INFO] [stderr]     Checking notify v4.0.15
[INFO] [stderr]     Checking console v0.7.7
[INFO] [stderr]     Checking indicatif v0.10.3
[INFO] [stderr]     Checking serde_json v1.0.59
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking rustlings v4.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 19.50s
[INFO] running `Command { std: "docker" "inspect" "30fbadbbcc8f8ac6c299107f035595b611b99e29438e180628676f3ac84ed48b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "30fbadbbcc8f8ac6c299107f035595b611b99e29438e180628676f3ac84ed48b", kill_on_drop: false }`
[INFO] [stdout] 30fbadbbcc8f8ac6c299107f035595b611b99e29438e180628676f3ac84ed48b