[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 master#3cdcdaf31b45f8045164aae9604573d23091970b for pr-122267
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/initinll-rust/learning-smart-pointers on toolchain 3cdcdaf31b45f8045164aae9604573d23091970b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3cdcdaf31b45f8045164aae9604573d23091970b" "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-4-tc1/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" "+3cdcdaf31b45f8045164aae9604573d23091970b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking initinll-rust/learning-smart-pointers against try#05804f728f276cf7ecedbf71c814df440d37f293 for pr-122267
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/initinll-rust/learning-smart-pointers on toolchain 05804f728f276cf7ecedbf71c814df440d37f293
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+05804f728f276cf7ecedbf71c814df440d37f293" "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-4-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" "+05804f728f276cf7ecedbf71c814df440d37f293" "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#05804f728f276cf7ecedbf71c814df440d37f293 for pr-122267
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Finitinll-rust%2Flearning-smart-pointers" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/initinll-rust/learning-smart-pointers on toolchain 05804f728f276cf7ecedbf71c814df440d37f293
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+05804f728f276cf7ecedbf71c814df440d37f293" "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-4-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" "+05804f728f276cf7ecedbf71c814df440d37f293" "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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+05804f728f276cf7ecedbf71c814df440d37f293" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a989c66f8c70fbefb33bd20e070c4c6a5e56ae81420c2566b018434e1800dbc4
[INFO] running `Command { std: "docker" "start" "-a" "a989c66f8c70fbefb33bd20e070c4c6a5e56ae81420c2566b018434e1800dbc4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a989c66f8c70fbefb33bd20e070c4c6a5e56ae81420c2566b018434e1800dbc4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a989c66f8c70fbefb33bd20e070c4c6a5e56ae81420c2566b018434e1800dbc4", kill_on_drop: false }`
[INFO] [stdout] a989c66f8c70fbefb33bd20e070c4c6a5e56ae81420c2566b018434e1800dbc4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+05804f728f276cf7ecedbf71c814df440d37f293" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2241fa11bd0bd00c22abae32161d8899a0fa421f66fb33289eb0a20b4d660565
[INFO] running `Command { std: "docker" "start" "-a" "2241fa11bd0bd00c22abae32161d8899a0fa421f66fb33289eb0a20b4d660565", 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: `#[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((), ()),
[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] 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((), ()),
[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: `#[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((), ()),
[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] 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((), ()),
[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: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.06s
[INFO] running `Command { std: "docker" "inspect" "2241fa11bd0bd00c22abae32161d8899a0fa421f66fb33289eb0a20b4d660565", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2241fa11bd0bd00c22abae32161d8899a0fa421f66fb33289eb0a20b4d660565", kill_on_drop: false }`
[INFO] [stdout] 2241fa11bd0bd00c22abae32161d8899a0fa421f66fb33289eb0a20b4d660565