[INFO] cloning repository https://github.com/0xSaksham/reference_cycle
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/0xSaksham/reference_cycle" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xSaksham%2Freference_cycle", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xSaksham%2Freference_cycle'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 40b970ebecf94381b3a4a19e2b6eef99f12595d7
[INFO] checking 0xSaksham/reference_cycle against try#5fee451ebd94296ea05214e819c311e164b30af6 for pr-139042
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2F0xSaksham%2Freference_cycle" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/0xSaksham/reference_cycle on toolchain 5fee451ebd94296ea05214e819c311e164b30af6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/0xSaksham/reference_cycle
[INFO] finished tweaking git repo https://github.com/0xSaksham/reference_cycle
[INFO] tweaked toml for git repo https://github.com/0xSaksham/reference_cycle written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/0xSaksham/reference_cycle 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" "+5fee451ebd94296ea05214e819c311e164b30af6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4ec0e6db24b1ff7bc62e7e474c4e6a087e796683cdddf368dc59be189ccd0308
[INFO] running `Command { std: "docker" "start" "-a" "4ec0e6db24b1ff7bc62e7e474c4e6a087e796683cdddf368dc59be189ccd0308", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4ec0e6db24b1ff7bc62e7e474c4e6a087e796683cdddf368dc59be189ccd0308", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ec0e6db24b1ff7bc62e7e474c4e6a087e796683cdddf368dc59be189ccd0308", kill_on_drop: false }`
[INFO] [stdout] 4ec0e6db24b1ff7bc62e7e474c4e6a087e796683cdddf368dc59be189ccd0308
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:4b26683ee3c49f365255c425c23003cbf4366de097804722c29c5bbbee3624d2" "/opt/rustwide/cargo-home/bin/cargo" "+5fee451ebd94296ea05214e819c311e164b30af6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 60035a5111ba0bfb285978c4fc1c1307b32c05eb140f1279be222b54928627cf
[INFO] running `Command { std: "docker" "start" "-a" "60035a5111ba0bfb285978c4fc1c1307b32c05eb140f1279be222b54928627cf", kill_on_drop: false }`
[INFO] [stderr]     Checking reference_cycle v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/main.rs:6:10
[INFO] [stdout]   |
[INFO] [stdout] 6 |     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |     ---- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 6 -     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 6 +     Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/main.rs:6:10
[INFO] [stdout]   |
[INFO] [stdout] 6 |     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |     ---- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 6 -     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 6 +     Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] running `Command { std: "docker" "inspect" "60035a5111ba0bfb285978c4fc1c1307b32c05eb140f1279be222b54928627cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60035a5111ba0bfb285978c4fc1c1307b32c05eb140f1279be222b54928627cf", kill_on_drop: false }`
[INFO] [stdout] 60035a5111ba0bfb285978c4fc1c1307b32c05eb140f1279be222b54928627cf
