[INFO] cloning repository https://github.com/arunkumar-reddy/Rust-Intro
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/arunkumar-reddy/Rust-Intro" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farunkumar-reddy%2FRust-Intro", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farunkumar-reddy%2FRust-Intro'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 73e291e75bfee1cb3553d9dbc3febc54205007b7
[INFO] checking arunkumar-reddy/Rust-Intro against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farunkumar-reddy%2FRust-Intro" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/arunkumar-reddy/Rust-Intro on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/arunkumar-reddy/Rust-Intro
[INFO] finished tweaking git repo https://github.com/arunkumar-reddy/Rust-Intro
[INFO] tweaked toml for git repo https://github.com/arunkumar-reddy/Rust-Intro written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/arunkumar-reddy/Rust-Intro already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d5cc5c65b3b763cef3751a7f48e49f7e498e117bdf06645f1034230624f193cb
[INFO] running `Command { std: "docker" "start" "-a" "d5cc5c65b3b763cef3751a7f48e49f7e498e117bdf06645f1034230624f193cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d5cc5c65b3b763cef3751a7f48e49f7e498e117bdf06645f1034230624f193cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d5cc5c65b3b763cef3751a7f48e49f7e498e117bdf06645f1034230624f193cb", kill_on_drop: false }`
[INFO] [stdout] d5cc5c65b3b763cef3751a7f48e49f7e498e117bdf06645f1034230624f193cb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dabf1762a65c2fe3c98cbdec61b9d5f853e39adcffae7d4e9ae1e2f4f766d9b1
[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" "dabf1762a65c2fe3c98cbdec61b9d5f853e39adcffae7d4e9ae1e2f4f766d9b1", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.78
[INFO] [stderr]    Compiling syn v1.0.42
[INFO] [stderr]    Compiling pin-project-internal v0.4.25
[INFO] [stderr]     Checking tracing v0.1.21
[INFO] [stderr]     Checking want v0.3.0
[INFO] [stderr]     Checking serde_urlencoded v0.6.1
[INFO] [stderr]     Checking net2 v0.2.35
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[INFO] [stderr]     Checking openssl-sys v0.9.58
[INFO] [stderr]     Checking socket2 v0.3.15
[INFO] [stderr]     Checking mio v0.6.22
[INFO] [stderr]     Checking openssl v0.10.30
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking native-tls v0.2.4
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling futures-macro v0.3.5
[INFO] [stderr]     Checking tokio v0.2.22
[INFO] [stderr]     Checking pin-project v0.4.25
[INFO] [stderr]     Checking futures-util v0.3.5
[INFO] [stderr]     Checking tokio-util v0.3.1
[INFO] [stderr]     Checking tokio-tls v0.3.1
[INFO] [stderr]     Checking h2 v0.2.6
[INFO] [stderr]     Checking futures-executor v0.3.5
[INFO] [stderr]     Checking futures v0.3.5
[INFO] [stderr]     Checking hyper v0.13.8
[INFO] [stderr]     Checking hyper-tls v0.4.3
[INFO] [stderr]     Checking reqwest v0.10.8
[INFO] [stderr]     Checking rust_intro v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]   --> src/async_await/mod.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let res = match res {
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/linked_list/mod.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(value: u32) -> Node {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `search`
[INFO] [stdout]   --> src/bst/mod.rs:46:12
[INFO] [stdout]    |
[INFO] [stdout] 46 |     pub fn search(&self, val: i32) -> Option<&Node> {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `search`
[INFO] [stdout]    --> src/bst/mod.rs:141:12
[INFO] [stdout]     |
[INFO] [stdout] 141 |     pub fn search(&self, val: i32) -> Option<&Node> {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]   --> src/async_await/mod.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let res = match res {
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/linked_list/mod.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(value: u32) -> Node {
[INFO] [stdout]    |            ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `search`
[INFO] [stdout]   --> src/bst/mod.rs:46:12
[INFO] [stdout]    |
[INFO] [stdout] 46 |     pub fn search(&self, val: i32) -> Option<&Node> {
[INFO] [stdout]    |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `search`
[INFO] [stdout]    --> src/bst/mod.rs:141:12
[INFO] [stdout]     |
[INFO] [stdout] 141 |     pub fn search(&self, val: i32) -> Option<&Node> {
[INFO] [stdout]     |            ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 55.03s
[INFO] running `Command { std: "docker" "inspect" "dabf1762a65c2fe3c98cbdec61b9d5f853e39adcffae7d4e9ae1e2f4f766d9b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dabf1762a65c2fe3c98cbdec61b9d5f853e39adcffae7d4e9ae1e2f4f766d9b1", kill_on_drop: false }`
[INFO] [stdout] dabf1762a65c2fe3c98cbdec61b9d5f853e39adcffae7d4e9ae1e2f4f766d9b1