[INFO] cloning repository https://github.com/cedricleroy/rust-tuto
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/cedricleroy/rust-tuto" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcedricleroy%2Frust-tuto", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcedricleroy%2Frust-tuto'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ca031c3e4b110d5556de9e56ec2e2541af3f0402
[INFO] checking cedricleroy/rust-tuto against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcedricleroy%2Frust-tuto" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/cedricleroy/rust-tuto 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/cedricleroy/rust-tuto
[INFO] finished tweaking git repo https://github.com/cedricleroy/rust-tuto
[INFO] tweaked toml for git repo https://github.com/cedricleroy/rust-tuto written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/cedricleroy/rust-tuto 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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_json v1.0.31
[INFO] [stderr]   Downloaded serde v1.0.79
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0c0695ce9482a7362c16d9b16bb312ca7ebd8c53695f4626be91d4b28442f652
[INFO] running `Command { std: "docker" "start" "-a" "0c0695ce9482a7362c16d9b16bb312ca7ebd8c53695f4626be91d4b28442f652", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0c0695ce9482a7362c16d9b16bb312ca7ebd8c53695f4626be91d4b28442f652", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0c0695ce9482a7362c16d9b16bb312ca7ebd8c53695f4626be91d4b28442f652", kill_on_drop: false }`
[INFO] [stdout] 0c0695ce9482a7362c16d9b16bb312ca7ebd8c53695f4626be91d4b28442f652
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] 4f69dfcfe56fb830907a32f1932b056180483deb9583a23d61a954fb92746607
[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" "4f69dfcfe56fb830907a32f1932b056180483deb9583a23d61a954fb92746607", kill_on_drop: false }`
[INFO] [stderr]    Compiling ryu v0.2.6
[INFO] [stderr]    Compiling serde v1.0.79
[INFO] [stderr]     Checking itoa v0.4.3
[INFO] [stderr]     Checking serde_json v1.0.31
[INFO] [stderr]     Checking rust-tuto v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `y` is never read
[INFO] [stdout]   --> src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let mut y = 21;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `y` is never read
[INFO] [stdout]   --> src/main.rs:13:9
[INFO] [stdout]    |
[INFO] [stdout] 13 |     let mut y = 21;
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/json.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     file.read_to_string(&mut content);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/json.rs:12:5
[INFO] [stdout]    |
[INFO] [stdout] 12 |     file.read_to_string(&mut content);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 11.83s
[INFO] running `Command { std: "docker" "inspect" "4f69dfcfe56fb830907a32f1932b056180483deb9583a23d61a954fb92746607", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f69dfcfe56fb830907a32f1932b056180483deb9583a23d61a954fb92746607", kill_on_drop: false }`
[INFO] [stdout] 4f69dfcfe56fb830907a32f1932b056180483deb9583a23d61a954fb92746607