[INFO] cloning repository https://github.com/hon/study_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hon/study_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhon%2Fstudy_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhon%2Fstudy_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fd7f5c6e1dc451214c9990f6c839ac755c1709fb
[INFO] checking hon/study_rust against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhon%2Fstudy_rust" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hon/study_rust 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/hon/study_rust
[INFO] finished tweaking git repo https://github.com/hon/study_rust
[INFO] tweaked toml for git repo https://github.com/hon/study_rust written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/hon/study_rust 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 48abb343e981e7fb94108a8210d7ad22b25945185ac8276b8122020c55d5e09e
[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" "48abb343e981e7fb94108a8210d7ad22b25945185ac8276b8122020c55d5e09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "48abb343e981e7fb94108a8210d7ad22b25945185ac8276b8122020c55d5e09e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48abb343e981e7fb94108a8210d7ad22b25945185ac8276b8122020c55d5e09e", kill_on_drop: false }`
[INFO] [stdout] 48abb343e981e7fb94108a8210d7ad22b25945185ac8276b8122020c55d5e09e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a4a68663ab8ff2b1fc543c6d708701665f92ca82ee496fc76a38a6114187f2ae
[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" "a4a68663ab8ff2b1fc543c6d708701665f92ca82ee496fc76a38a6114187f2ae", kill_on_drop: false }`
[INFO] [stderr]     Checking study_rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `consume`
[INFO] [stdout]   --> src/s_closure/mod.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let consume = || {
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_consume`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]  --> src/s_mutability/mod.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut x = 5;
[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 variable: `consume`
[INFO] [stdout]   --> src/s_closure/mod.rs:61:9
[INFO] [stdout]    |
[INFO] [stdout] 61 |     let consume = || {
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_consume`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `x` is never read
[INFO] [stdout]  --> src/s_mutability/mod.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |     let mut x = 5;
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.24s
[INFO] running `Command { std: "docker" "inspect" "a4a68663ab8ff2b1fc543c6d708701665f92ca82ee496fc76a38a6114187f2ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a4a68663ab8ff2b1fc543c6d708701665f92ca82ee496fc76a38a6114187f2ae", kill_on_drop: false }`
[INFO] [stdout] a4a68663ab8ff2b1fc543c6d708701665f92ca82ee496fc76a38a6114187f2ae