[INFO] cloning repository https://github.com/emmanuel2406/Rust_projects-rc
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/emmanuel2406/Rust_projects-rc" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femmanuel2406%2FRust_projects-rc", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femmanuel2406%2FRust_projects-rc'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1ba1b4289d936145c8820f7335d90f25840e6f73
[INFO] checking emmanuel2406/Rust_projects-rc against master#cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c for pr-143170
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femmanuel2406%2FRust_projects-rc" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/emmanuel2406/Rust_projects-rc
[INFO] finished tweaking git repo https://github.com/emmanuel2406/Rust_projects-rc
[INFO] tweaked toml for git repo https://github.com/emmanuel2406/Rust_projects-rc written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/emmanuel2406/Rust_projects-rc on toolchain cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/emmanuel2406/Rust_projects-rc 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" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "fetch" "--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-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2499e1ca72c63c6496caab12b2facb8dc0155427336a693589c6285e2cbb5c8e
[INFO] running `Command { std: "docker" "start" "-a" "2499e1ca72c63c6496caab12b2facb8dc0155427336a693589c6285e2cbb5c8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2499e1ca72c63c6496caab12b2facb8dc0155427336a693589c6285e2cbb5c8e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2499e1ca72c63c6496caab12b2facb8dc0155427336a693589c6285e2cbb5c8e", kill_on_drop: false }`
[INFO] [stdout] 2499e1ca72c63c6496caab12b2facb8dc0155427336a693589c6285e2cbb5c8e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+cf38b8e663f15db10ce49d7bbce02c99fc3dbc0c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2d22c862f83e1b345de983c67c3df0e8b0317971d11287ed8f832672383527d5
[INFO] running `Command { std: "docker" "start" "-a" "2d22c862f83e1b345de983c67c3df0e8b0317971d11287ed8f832672383527d5", kill_on_drop: false }`
[INFO] [stderr]     Checking rc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let c = Cons(Rc::new(RefCell::new(4)), Rc::clone(&a));
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/main.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]   |     ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields 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 fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 3 -     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout] 3 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `c`
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let c = Cons(Rc::new(RefCell::new(4)), Rc::clone(&a));
[INFO] [stdout]    |             ^ help: if this is intentional, prefix it with an underscore: `_c`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/main.rs:3:10
[INFO] [stdout]   |
[INFO] [stdout] 3 |     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]   |     ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields 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 fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]   |
[INFO] [stdout] 3 -     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout] 3 +     Cons((), ()),
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.22s
[INFO] running `Command { std: "docker" "inspect" "2d22c862f83e1b345de983c67c3df0e8b0317971d11287ed8f832672383527d5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d22c862f83e1b345de983c67c3df0e8b0317971d11287ed8f832672383527d5", kill_on_drop: false }`
[INFO] [stdout] 2d22c862f83e1b345de983c67c3df0e8b0317971d11287ed8f832672383527d5