[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] checking a74946443/learn_rust/d4214616a24e50a567a83e50cca030906d5f2a9f against master#ff1737bb00913444173658b4e0b274fd79aabf66 for pr-132712-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/a74946443/learn_rust on toolchain ff1737bb00913444173658b4e0b274fd79aabf66
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "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-6-tc1/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: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded simple_redis v0.3.44
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4e3ee835e27d7788a647cee6968ad85b49e0b20eaedbb9e80d737c8702523e7d
[INFO] running `Command { std: "docker" "start" "-a" "4e3ee835e27d7788a647cee6968ad85b49e0b20eaedbb9e80d737c8702523e7d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4e3ee835e27d7788a647cee6968ad85b49e0b20eaedbb9e80d737c8702523e7d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e3ee835e27d7788a647cee6968ad85b49e0b20eaedbb9e80d737c8702523e7d", kill_on_drop: false }`
[INFO] [stdout] 4e3ee835e27d7788a647cee6968ad85b49e0b20eaedbb9e80d737c8702523e7d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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=allow" "-e" "RUSTDOCFLAGS=--cap-lints=allow" "-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@sha256:4a844ea9eb2546a2d2c7022eacef16ef2e8229c7fbb2c7d4d55a9ceca922f72d" "/opt/rustwide/cargo-home/bin/cargo" "+ff1737bb00913444173658b4e0b274fd79aabf66" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 08b624fd0ecc05b746e8979a980caa50bddbe434f2bb70797bbd6de6bbd8e76d
[INFO] running `Command { std: "docker" "start" "-a" "08b624fd0ecc05b746e8979a980caa50bddbe434f2bb70797bbd6de6bbd8e76d", kill_on_drop: false }`
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]     Checking matches v0.1.8
[INFO] [stderr]    Compiling redis v0.8.0
[INFO] [stderr]     Checking percent-encoding v1.0.1
[INFO] [stderr]     Checking sha1 v0.2.0
[INFO] [stderr]     Checking unicode-bidi v0.3.4
[INFO] [stderr]     Checking unicode-normalization v0.1.8
[INFO] [stderr]     Checking idna v0.1.5
[INFO] [stderr]     Checking url v1.7.2
[INFO] [stderr]     Checking simple_redis v0.3.44
[INFO] [stderr]     Checking 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] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `learn_rust` (test "exercise") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "08b624fd0ecc05b746e8979a980caa50bddbe434f2bb70797bbd6de6bbd8e76d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08b624fd0ecc05b746e8979a980caa50bddbe434f2bb70797bbd6de6bbd8e76d", kill_on_drop: false }`
[INFO] [stdout] 08b624fd0ecc05b746e8979a980caa50bddbe434f2bb70797bbd6de6bbd8e76d