[INFO] cloning repository https://github.com/gannonchan/var_study
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gannonchan/var_study" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgannonchan%2Fvar_study", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgannonchan%2Fvar_study'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c4cb9303acf58bb7cb704d18f51352c088211811
[INFO] checking gannonchan/var_study against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgannonchan%2Fvar_study" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/gannonchan/var_study on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/gannonchan/var_study
[INFO] finished tweaking git repo https://github.com/gannonchan/var_study
[INFO] tweaked toml for git repo https://github.com/gannonchan/var_study written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/gannonchan/var_study already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 48478e0e72f5eb57884c2234fa9d36aa3e6278974f03b6c84dbca3351373e1ad
[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" "48478e0e72f5eb57884c2234fa9d36aa3e6278974f03b6c84dbca3351373e1ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "48478e0e72f5eb57884c2234fa9d36aa3e6278974f03b6c84dbca3351373e1ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48478e0e72f5eb57884c2234fa9d36aa3e6278974f03b6c84dbca3351373e1ad", kill_on_drop: false }`
[INFO] [stdout] 48478e0e72f5eb57884c2234fa9d36aa3e6278974f03b6c84dbca3351373e1ad
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 855b1bb6a982174821bca81886cd674f5bd840c1879e4d27ea1aaf87a83e9b6f
[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" "855b1bb6a982174821bca81886cd674f5bd840c1879e4d27ea1aaf87a83e9b6f", kill_on_drop: false }`
[INFO] [stderr]     Checking var_study v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `first_name`
[INFO] [stdout]   --> src/main.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let first_name = String::from("0");
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_first_name`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `last_name`
[INFO] [stdout]   --> src/main.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let last_name = String::from("张三");
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_last_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let f = match f {   //使用match判断打开文件是否出现错误
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:95:9
[INFO] [stdout]    |
[INFO] [stdout] 95 |     let f = File::open("d:\\hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     let f = File::open("d:\\hello.txt").expect("打开文件发生错误！");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `first_name`
[INFO] [stdout]   --> src/main.rs:23:9
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let first_name = String::from("0");
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_first_name`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `last_name`
[INFO] [stdout]   --> src/main.rs:24:9
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let last_name = String::from("张三");
[INFO] [stdout]    |         ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_last_name`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:73:9
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let f = match f {   //使用match判断打开文件是否出现错误
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:95:9
[INFO] [stdout]    |
[INFO] [stdout] 95 |     let f = File::open("d:\\hello.txt").unwrap();
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `f`
[INFO] [stdout]   --> src/main.rs:97:9
[INFO] [stdout]    |
[INFO] [stdout] 97 |     let f = File::open("d:\\hello.txt").expect("打开文件发生错误！");
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_f`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.35s
[INFO] running `Command { std: "docker" "inspect" "855b1bb6a982174821bca81886cd674f5bd840c1879e4d27ea1aaf87a83e9b6f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "855b1bb6a982174821bca81886cd674f5bd840c1879e4d27ea1aaf87a83e9b6f", kill_on_drop: false }`
[INFO] [stdout] 855b1bb6a982174821bca81886cd674f5bd840c1879e4d27ea1aaf87a83e9b6f