[INFO] cloning repository https://github.com/initinll-rust/learning-smart-pointers
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/initinll-rust/learning-smart-pointers" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9d22c3b011e83076e16c4af782407234799c1934
[INFO] checking initinll-rust/learning-smart-pointers against try#411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51 for pr-138844
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/initinll-rust/learning-smart-pointers on toolchain 411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/initinll-rust/learning-smart-pointers
[INFO] finished tweaking git repo https://github.com/initinll-rust/learning-smart-pointers
[INFO] tweaked toml for git repo https://github.com/initinll-rust/learning-smart-pointers written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/initinll-rust/learning-smart-pointers 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" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking initinll-rust/learning-smart-pointers against try#411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51 for pr-138844
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/initinll-rust/learning-smart-pointers on toolchain 411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/initinll-rust/learning-smart-pointers
[INFO] finished tweaking git repo https://github.com/initinll-rust/learning-smart-pointers
[INFO] tweaked toml for git repo https://github.com/initinll-rust/learning-smart-pointers written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/initinll-rust/learning-smart-pointers 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" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 40f4cd132db8f4ba5b59e0d2e9c3e9fd107f4a0e4be77b72a08d71cd827c8281
[INFO] running `Command { std: "docker" "start" "-a" "40f4cd132db8f4ba5b59e0d2e9c3e9fd107f4a0e4be77b72a08d71cd827c8281", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "40f4cd132db8f4ba5b59e0d2e9c3e9fd107f4a0e4be77b72a08d71cd827c8281", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "40f4cd132db8f4ba5b59e0d2e9c3e9fd107f4a0e4be77b72a08d71cd827c8281", kill_on_drop: false }`
[INFO] [stdout] 40f4cd132db8f4ba5b59e0d2e9c3e9fd107f4a0e4be77b72a08d71cd827c8281
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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" "+411f3ca0d8086d5a27e2aaa79b9ff41f53ab2f51" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 80c1e19a3cf3eec4f046f531d24d200633b448db297719e1672fa567d0995eb2
[INFO] running `Command { std: "docker" "start" "-a" "80c1e19a3cf3eec4f046f531d24d200633b448db297719e1672fa567d0995eb2", kill_on_drop: false }`
[INFO] [stderr]     Checking learning-smart-pointers v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_box_concepts.rs:29:10
[INFO] [stdout]    |
[INFO] [stdout] 29 |     Cons(i32, Box<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] 29 -     Cons(i32, Box<List>),
[INFO] [stdout] 29 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_rc_concepts.rs:43:10
[INFO] [stdout]    |
[INFO] [stdout] 43 |     Cons(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] 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] 43 -     Cons(i32, Rc<List>),
[INFO] [stdout] 43 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_rc_weak_prevent_reference_cycles_concepts.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 9  | struct Node {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 10 |     value: i32, // value of the node
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 11 |     parent: RefCell<Weak<Node>>, // a node has single parent, weak reference as child should not own its parent 
[INFO] [stdout] 12 |     children: RefCell<Vec<Rc<Node>>> // a node can have multiple children, strong reference as parent should own its children
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_box_concepts.rs:29:10
[INFO] [stdout]    |
[INFO] [stdout] 29 |     Cons(i32, Box<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] 29 -     Cons(i32, Box<List>),
[INFO] [stdout] 29 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_rc_concepts.rs:43:10
[INFO] [stdout]    |
[INFO] [stdout] 43 |     Cons(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] 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] 43 -     Cons(i32, Rc<List>),
[INFO] [stdout] 43 +     Cons((), ()),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> src/single_threaded/smart_pointer_rc_weak_prevent_reference_cycles_concepts.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 9  | struct Node {
[INFO] [stdout]    |        ---- fields in this struct
[INFO] [stdout] 10 |     value: i32, // value of the node
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout] 11 |     parent: RefCell<Weak<Node>>, // a node has single parent, weak reference as child should not own its parent 
[INFO] [stdout] 12 |     children: RefCell<Vec<Rc<Node>>> // a node can have multiple children, strong reference as parent should own its children
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.13s
[INFO] running `Command { std: "docker" "inspect" "80c1e19a3cf3eec4f046f531d24d200633b448db297719e1672fa567d0995eb2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "80c1e19a3cf3eec4f046f531d24d200633b448db297719e1672fa567d0995eb2", kill_on_drop: false }`
[INFO] [stdout] 80c1e19a3cf3eec4f046f531d24d200633b448db297719e1672fa567d0995eb2