[INFO] cloning repository https://github.com/a74946443/learn_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/a74946443/learn_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d4214616a24e50a567a83e50cca030906d5f2a9f
[INFO] testing a74946443/learn_rust against master#432e145bd5a974c5b6f4dd9b352891bd7502b69d for pr-87041
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/a74946443/learn_rust on toolchain 432e145bd5a974c5b6f4dd9b352891bd7502b69d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/a74946443/learn_rust
[INFO] finished tweaking git repo https://github.com/a74946443/learn_rust
[INFO] tweaked toml for git repo https://github.com/a74946443/learn_rust written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/a74946443/learn_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "fetch" "--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-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "metadata" "--no-deps" "--format-version=1", 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] b15c15ae2421a6142ee63a7fc3b759ddd34858faa936146b5e6ae12f5a96c6d2
[INFO] running `Command { std: "docker" "start" "-a" "b15c15ae2421a6142ee63a7fc3b759ddd34858faa936146b5e6ae12f5a96c6d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b15c15ae2421a6142ee63a7fc3b759ddd34858faa936146b5e6ae12f5a96c6d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b15c15ae2421a6142ee63a7fc3b759ddd34858faa936146b5e6ae12f5a96c6d2", kill_on_drop: false }`
[INFO] [stdout] b15c15ae2421a6142ee63a7fc3b759ddd34858faa936146b5e6ae12f5a96c6d2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "build" "--frozen" "--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] 48c929ecb5b0d4752d2c35d00fdab52da52baa16089352a9389090450fb78ae0
[INFO] running `Command { std: "docker" "start" "-a" "48c929ecb5b0d4752d2c35d00fdab52da52baa16089352a9389090450fb78ae0", kill_on_drop: false }`
[INFO] [stderr]    Compiling matches v0.1.8
[INFO] [stderr]    Compiling redis v0.8.0
[INFO] [stderr]    Compiling percent-encoding v1.0.1
[INFO] [stderr]    Compiling sha1 v0.2.0
[INFO] [stderr]    Compiling unicode-bidi v0.3.4
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling url v1.7.2
[INFO] [stderr]    Compiling simple_redis v0.3.44
[INFO] [stderr]    Compiling learn_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 12.60s
[INFO] running `Command { std: "docker" "inspect" "48c929ecb5b0d4752d2c35d00fdab52da52baa16089352a9389090450fb78ae0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48c929ecb5b0d4752d2c35d00fdab52da52baa16089352a9389090450fb78ae0", kill_on_drop: false }`
[INFO] [stdout] 48c929ecb5b0d4752d2c35d00fdab52da52baa16089352a9389090450fb78ae0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+432e145bd5a974c5b6f4dd9b352891bd7502b69d" "test" "--frozen" "--no-run" "--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] 8c124665b13952f22e103905cf870b3556a121fbef067e2552ec0c3bd65dd8f9
[INFO] running `Command { std: "docker" "start" "-a" "8c124665b13952f22e103905cf870b3556a121fbef067e2552ec0c3bd65dd8f9", kill_on_drop: false }`
[INFO] [stderr]    Compiling learn_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `learn_rust::exercise::length_of_longest_substring::substring`
[INFO] [stdout]   --> tests/exercise.rs:16:9
[INFO] [stdout]    |
[INFO] [stdout] 16 |     use learn_rust::exercise::length_of_longest_substring::substring;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no `substring` in `exercise::length_of_longest_substring`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `learn_rust`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "8c124665b13952f22e103905cf870b3556a121fbef067e2552ec0c3bd65dd8f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c124665b13952f22e103905cf870b3556a121fbef067e2552ec0c3bd65dd8f9", kill_on_drop: false }`
[INFO] [stdout] 8c124665b13952f22e103905cf870b3556a121fbef067e2552ec0c3bd65dd8f9