[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 against master#db1fb85cff63ad5fffe435e17128f99f9e1d970c for pr-89056
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fa74946443%2Flearn_rust" "/workspace/builds/worker-112/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-112/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/a74946443/learn_rust on toolchain db1fb85cff63ad5fffe435e17128f99f9e1d970c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "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-112/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" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded redis v0.8.0
[INFO] [stderr]   Downloaded simple_redis v0.3.44
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] db6c0db040e90f99befed0adbfae6a7b329eef879ef6ceeff5a687b7d6b5c235
[INFO] running `Command { std: "docker" "start" "-a" "db6c0db040e90f99befed0adbfae6a7b329eef879ef6ceeff5a687b7d6b5c235", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "db6c0db040e90f99befed0adbfae6a7b329eef879ef6ceeff5a687b7d6b5c235", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "db6c0db040e90f99befed0adbfae6a7b329eef879ef6ceeff5a687b7d6b5c235", kill_on_drop: false }`
[INFO] [stdout] db6c0db040e90f99befed0adbfae6a7b329eef879ef6ceeff5a687b7d6b5c235
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-112/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 056f511b32d9676cf03a87cea228050d048fb0e5de3fd25ac343f9677a7ac0a0
[INFO] running `Command { std: "docker" "start" "-a" "056f511b32d9676cf03a87cea228050d048fb0e5de3fd25ac343f9677a7ac0a0", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]    Compiling redis v0.8.0
[INFO] [stderr]     Checking sha1 v0.2.0
[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] 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` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "056f511b32d9676cf03a87cea228050d048fb0e5de3fd25ac343f9677a7ac0a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "056f511b32d9676cf03a87cea228050d048fb0e5de3fd25ac343f9677a7ac0a0", kill_on_drop: false }`
[INFO] [stdout] 056f511b32d9676cf03a87cea228050d048fb0e5de3fd25ac343f9677a7ac0a0