[INFO] cloning repository https://github.com/Dhole/rust_learning
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Dhole/rust_learning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDhole%2Frust_learning", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDhole%2Frust_learning'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d05e463827e5ebb860a379c3714631acf7e3d728
[INFO] checking Dhole/rust_learning against try#b2f80f6008cdafc35b4472bd46afa16cc6b0cd63 for pr-79470
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDhole%2Frust_learning" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Dhole/rust_learning on toolchain b2f80f6008cdafc35b4472bd46afa16cc6b0cd63
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Dhole/rust_learning
[INFO] finished tweaking git repo https://github.com/Dhole/rust_learning
[INFO] tweaked toml for git repo https://github.com/Dhole/rust_learning written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/Dhole/rust_learning already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f9291b1bc5357873074e50c01936cb810628f3bbfa091ca19c85b79259a00edc
[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" "f9291b1bc5357873074e50c01936cb810628f3bbfa091ca19c85b79259a00edc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f9291b1bc5357873074e50c01936cb810628f3bbfa091ca19c85b79259a00edc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f9291b1bc5357873074e50c01936cb810628f3bbfa091ca19c85b79259a00edc", kill_on_drop: false }`
[INFO] [stdout] f9291b1bc5357873074e50c01936cb810628f3bbfa091ca19c85b79259a00edc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f0d90476214c296711d0d5eb41a905c0db21f314ed428a742cac29d9cdb8c764
[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" "f0d90476214c296711d0d5eb41a905c0db21f314ed428a742cac29d9cdb8c764", kill_on_drop: false }`
[INFO] [stderr]     Checking learn v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0432]: unresolved import `std::rand`
[INFO] [stdout]   --> src/main.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 | use std::rand;
[INFO] [stdout]    |     ^^^^^^^^^ no `rand` in the root
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::rand`
[INFO] [stdout]   --> src/main.rs:54:10
[INFO] [stdout]    |
[INFO] [stdout] 54 | use std::rand::Rng;
[INFO] [stdout]    |          ^^^^ could not find `rand` in `std`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::rand`
[INFO] [stdout]   --> src/main.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 | use std::rand;
[INFO] [stdout]    |     ^^^^^^^^^ no `rand` in the root
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `std::rand`
[INFO] [stdout]   --> src/main.rs:54:10
[INFO] [stdout]    |
[INFO] [stdout] 54 | use std::rand::Rng;
[INFO] [stdout]    |          ^^^^ could not find `rand` in `std`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `learn`
[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] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "f0d90476214c296711d0d5eb41a905c0db21f314ed428a742cac29d9cdb8c764", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f0d90476214c296711d0d5eb41a905c0db21f314ed428a742cac29d9cdb8c764", kill_on_drop: false }`
[INFO] [stdout] f0d90476214c296711d0d5eb41a905c0db21f314ed428a742cac29d9cdb8c764