[INFO] updating cached 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" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d4214616a24e50a567a83e50cca030906d5f2a9f
[INFO] testing a74946443/learn_rust against 1.45.2 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust" "/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/a74946443/learn_rust on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", 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-4/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" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a6ebbad542e73e137f221ffc18ef2f212f154057c8b6c37dadf825a67611291
[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" "1a6ebbad542e73e137f221ffc18ef2f212f154057c8b6c37dadf825a67611291", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a6ebbad542e73e137f221ffc18ef2f212f154057c8b6c37dadf825a67611291", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a6ebbad542e73e137f221ffc18ef2f212f154057c8b6c37dadf825a67611291", kill_on_drop: false }`
[INFO] [stdout] 1a6ebbad542e73e137f221ffc18ef2f212f154057c8b6c37dadf825a67611291
[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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] 747345dd85e2fa6f3e7dc7565fa38226be083fa92cef06f29406725e9fee9488
[INFO] running `Command { std: "docker" "start" "-a" "747345dd85e2fa6f3e7dc7565fa38226be083fa92cef06f29406725e9fee9488", kill_on_drop: false }`
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling matches v0.1.8
[INFO] [stderr]    Compiling percent-encoding v1.0.1
[INFO] [stderr]    Compiling redis v0.8.0
[INFO] [stderr]    Compiling sha1 v0.2.0
[INFO] [stderr]    Compiling unicode-bidi v0.3.4
[INFO] [stderr]    Compiling unicode-normalization v0.1.8
[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 14.18s
[INFO] running `Command { std: "docker" "inspect" "747345dd85e2fa6f3e7dc7565fa38226be083fa92cef06f29406725e9fee9488", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "747345dd85e2fa6f3e7dc7565fa38226be083fa92cef06f29406725e9fee9488", kill_on_drop: false }`
[INFO] [stdout] 747345dd85e2fa6f3e7dc7565fa38226be083fa92cef06f29406725e9fee9488
[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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] 3c631931b28e994aa2094c3566e7b357d5924835ad4c0fc4b9bb143e08a68ebb
[INFO] running `Command { std: "docker" "start" "-a" "3c631931b28e994aa2094c3566e7b357d5924835ad4c0fc4b9bb143e08a68ebb", 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" "3c631931b28e994aa2094c3566e7b357d5924835ad4c0fc4b9bb143e08a68ebb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3c631931b28e994aa2094c3566e7b357d5924835ad4c0fc4b9bb143e08a68ebb", kill_on_drop: false }`
[INFO] [stdout] 3c631931b28e994aa2094c3566e7b357d5924835ad4c0fc4b9bb143e08a68ebb