[INFO] cloning repository https://github.com/knissley/basic-rust-examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/knissley/basic-rust-examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fknissley%2Fbasic-rust-examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fknissley%2Fbasic-rust-examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] eb3912e2b99e57591a6f3b81dd3ad34d1c70fefb
[INFO] checking knissley/basic-rust-examples against master#43ca9d18e333797f0aa3b525501a7cec8d61a96b for pr-136764
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fknissley%2Fbasic-rust-examples" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/knissley/basic-rust-examples on toolchain 43ca9d18e333797f0aa3b525501a7cec8d61a96b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+43ca9d18e333797f0aa3b525501a7cec8d61a96b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/knissley/basic-rust-examples
[INFO] finished tweaking git repo https://github.com/knissley/basic-rust-examples
[INFO] tweaked toml for git repo https://github.com/knissley/basic-rust-examples written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/knissley/basic-rust-examples 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" "+43ca9d18e333797f0aa3b525501a7cec8d61a96b" "fetch" "--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-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:3959728d45483eb673ba100a951a6b9f5012970368db2a9e08e0ac9b67c8a5ad" "/opt/rustwide/cargo-home/bin/cargo" "+43ca9d18e333797f0aa3b525501a7cec8d61a96b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4cf0d241bf3e6756fac72026c4a46ae58af1b36f317cae34f37d40d21acb9951
[INFO] running `Command { std: "docker" "start" "-a" "4cf0d241bf3e6756fac72026c4a46ae58af1b36f317cae34f37d40d21acb9951", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4cf0d241bf3e6756fac72026c4a46ae58af1b36f317cae34f37d40d21acb9951", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4cf0d241bf3e6756fac72026c4a46ae58af1b36f317cae34f37d40d21acb9951", kill_on_drop: false }`
[INFO] [stdout] 4cf0d241bf3e6756fac72026c4a46ae58af1b36f317cae34f37d40d21acb9951
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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=forbid" "-e" "RUSTDOCFLAGS=--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@sha256:3959728d45483eb673ba100a951a6b9f5012970368db2a9e08e0ac9b67c8a5ad" "/opt/rustwide/cargo-home/bin/cargo" "+43ca9d18e333797f0aa3b525501a7cec8d61a96b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dbe91a6340e88e375685173c955a3e8cf685d2d4890148036246e93efcd69f7c
[INFO] running `Command { std: "docker" "start" "-a" "dbe91a6340e88e375685173c955a3e8cf685d2d4890148036246e93efcd69f7c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.141
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.17
[INFO] [stderr]     Checking getrandom v0.2.9
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking rust_practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/toy_problems.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::collections::HashMap`
[INFO] [stdout]  --> src/toy_problems.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::collections::HashMap;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DIFFICULTIES` is never used
[INFO] [stdout]  --> src/toy_problems.rs:5:7
[INFO] [stdout]   |
[INFO] [stdout] 5 | const DIFFICULTIES: [&str; 3] = ["EASY", "MEDIUM", "HARD"];
[INFO] [stdout]   |       ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `CATEGORIES` is never used
[INFO] [stdout]  --> src/toy_problems.rs:6:7
[INFO] [stdout]   |
[INFO] [stdout] 6 | const CATEGORIES: [&str; 1] = ["Strings"];
[INFO] [stdout]   |       ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `DIFFICULTIES` is never used
[INFO] [stdout]  --> src/toy_problems.rs:5:7
[INFO] [stdout]   |
[INFO] [stdout] 5 | const DIFFICULTIES: [&str; 3] = ["EASY", "MEDIUM", "HARD"];
[INFO] [stdout]   |       ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: constant `CATEGORIES` is never used
[INFO] [stdout]  --> src/toy_problems.rs:6:7
[INFO] [stdout]   |
[INFO] [stdout] 6 | const CATEGORIES: [&str; 1] = ["Strings"];
[INFO] [stdout]   |       ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `difficulty` and `category` are never read
[INFO] [stdout]   --> src/toy_problems.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 9  | struct ToyProblem<'a> {
[INFO] [stdout]    |        ---------- fields in this struct
[INFO] [stdout] 10 |     name: &'a str,
[INFO] [stdout] 11 |     difficulty: &'a str,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout] 12 |     category: &'a str,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `difficulty` and `category` are never read
[INFO] [stdout]   --> src/toy_problems.rs:11:5
[INFO] [stdout]    |
[INFO] [stdout] 9  | struct ToyProblem<'a> {
[INFO] [stdout]    |        ---------- fields in this struct
[INFO] [stdout] 10 |     name: &'a str,
[INFO] [stdout] 11 |     difficulty: &'a str,
[INFO] [stdout]    |     ^^^^^^^^^^
[INFO] [stdout] 12 |     category: &'a str,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.02s
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[INFO] running `Command { std: "docker" "rm" "-f" "dbe91a6340e88e375685173c955a3e8cf685d2d4890148036246e93efcd69f7c", kill_on_drop: false }`
[INFO] [stdout] dbe91a6340e88e375685173c955a3e8cf685d2d4890148036246e93efcd69f7c