[INFO] cloning repository https://github.com/Sammy275/hackerrank_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Sammy275/hackerrank_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSammy275%2Fhackerrank_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSammy275%2Fhackerrank_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] da261f5827be5b2536e10c3192feef59810f1493
[INFO] checking Sammy275/hackerrank_rust against master#9fa580b1175018b0a276b0bc68f9827a106f7260 for pr-82565
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSammy275%2Fhackerrank_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/Sammy275/hackerrank_rust on toolchain 9fa580b1175018b0a276b0bc68f9827a106f7260
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Sammy275/hackerrank_rust
[INFO] finished tweaking git repo https://github.com/Sammy275/hackerrank_rust
[INFO] tweaked toml for git repo https://github.com/Sammy275/hackerrank_rust written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/Sammy275/hackerrank_rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f83b71bc882e5a1a1ee0f38f83988e97de330a3535f2c13ffd893264b1e72304
[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" "f83b71bc882e5a1a1ee0f38f83988e97de330a3535f2c13ffd893264b1e72304", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f83b71bc882e5a1a1ee0f38f83988e97de330a3535f2c13ffd893264b1e72304", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f83b71bc882e5a1a1ee0f38f83988e97de330a3535f2c13ffd893264b1e72304", kill_on_drop: false }`
[INFO] [stdout] f83b71bc882e5a1a1ee0f38f83988e97de330a3535f2c13ffd893264b1e72304
[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" "rustops/crates-build-env@sha256:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] efe61709988c9dc3e40ebb683c485a5f2e2ecb3b9f7a10bd224fc0415e319c60
[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" "efe61709988c9dc3e40ebb683c485a5f2e2ecb3b9f7a10bd224fc0415e319c60", kill_on_drop: false }`
[INFO] [stderr]     Checking challenges v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io`
[INFO] [stdout]  --> src/main.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io;
[INFO] [stdout]   |     ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0601]: `main` function not found in crate `challenges`
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::io;
[INFO] [stdout]   | ^^^^^^^^^^^^ consider adding a `main` function to `src/main.rs`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0601`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `challenges`
[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" "efe61709988c9dc3e40ebb683c485a5f2e2ecb3b9f7a10bd224fc0415e319c60", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "efe61709988c9dc3e40ebb683c485a5f2e2ecb3b9f7a10bd224fc0415e319c60", kill_on_drop: false }`
[INFO] [stdout] efe61709988c9dc3e40ebb683c485a5f2e2ecb3b9f7a10bd224fc0415e319c60