[INFO] cloning repository https://github.com/kgish/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kgish/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkgish%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkgish%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f306609b9c13265616ef9bc5d22d821f54556903
[INFO] checking kgish/rustlings against master#f82664191d0e8764b7435b9d72eb0e366b8b1464 for pr-83354
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkgish%2Frustlings" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kgish/rustlings on toolchain f82664191d0e8764b7435b9d72eb0e366b8b1464
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kgish/rustlings
[INFO] finished tweaking git repo https://github.com/kgish/rustlings
[INFO] tweaked toml for git repo https://github.com/kgish/rustlings written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/kgish/rustlings already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:4f92631de1aa59f8320307485d3b3c869a5c90ab1d76ce2cffab9807b8c9a1fb" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d85e4dba07ee93f220cabaf7b26896eaa6c4c40c25dcc177fda2c1df226cfc2c
[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" "d85e4dba07ee93f220cabaf7b26896eaa6c4c40c25dcc177fda2c1df226cfc2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d85e4dba07ee93f220cabaf7b26896eaa6c4c40c25dcc177fda2c1df226cfc2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d85e4dba07ee93f220cabaf7b26896eaa6c4c40c25dcc177fda2c1df226cfc2c", kill_on_drop: false }`
[INFO] [stdout] d85e4dba07ee93f220cabaf7b26896eaa6c4c40c25dcc177fda2c1df226cfc2c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:4f92631de1aa59f8320307485d3b3c869a5c90ab1d76ce2cffab9807b8c9a1fb" "/opt/rustwide/cargo-home/bin/cargo" "+f82664191d0e8764b7435b9d72eb0e366b8b1464" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b60647fc181bf16440098a6cb787bd083e401733e4990e18176cd297f8d93701
[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" "b60647fc181bf16440098a6cb787bd083e401733e4990e18176cd297f8d93701", kill_on_drop: false }`
[INFO] [stderr]     Checking smallvec v0.6.9
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking glob v0.3.0
[INFO] [stderr]     Checking regex-syntax v0.6.6
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]     Checking clicolors-control v0.2.0
[INFO] [stderr]     Checking filetime v0.2.5
[INFO] [stderr]     Checking inotify v0.6.1
[INFO] [stderr]    Compiling syn v0.15.34
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking parking_lot_core v0.5.0
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking parking_lot v0.8.0
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking notify v4.0.12
[INFO] [stderr]     Checking regex v0.2.11
[INFO] [stderr]     Checking regex v1.1.6
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]     Checking console v0.7.5
[INFO] [stderr]     Checking predicates v1.0.1
[INFO] [stderr]     Checking console v0.6.2
[INFO] [stderr]     Checking indicatif v0.9.0
[INFO] [stderr]     Checking serde v1.0.92
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking toml v0.4.10
[INFO] [stderr]     Checking escargot v0.4.0
[INFO] [stderr]     Checking rustlings v2.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 28.56s
[INFO] running `Command { std: "docker" "inspect" "b60647fc181bf16440098a6cb787bd083e401733e4990e18176cd297f8d93701", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b60647fc181bf16440098a6cb787bd083e401733e4990e18176cd297f8d93701", kill_on_drop: false }`
[INFO] [stdout] b60647fc181bf16440098a6cb787bd083e401733e4990e18176cd297f8d93701