[INFO] cloning repository https://github.com/tiny-browserbook/exercise-rendering-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tiny-browserbook/exercise-rendering-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftiny-browserbook%2Fexercise-rendering-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftiny-browserbook%2Fexercise-rendering-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 52ba96b59bd81422a97a8caa975f4f04a7e8f63e
[INFO] checking tiny-browserbook/exercise-rendering-tree against master#e9271846294c4ee5bd7706df68180320c0b5ff20 for pr-119820
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftiny-browserbook%2Fexercise-rendering-tree" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tiny-browserbook/exercise-rendering-tree on toolchain e9271846294c4ee5bd7706df68180320c0b5ff20
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+e9271846294c4ee5bd7706df68180320c0b5ff20" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tiny-browserbook/exercise-rendering-tree
[INFO] finished tweaking git repo https://github.com/tiny-browserbook/exercise-rendering-tree
[INFO] tweaked toml for git repo https://github.com/tiny-browserbook/exercise-rendering-tree written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/tiny-browserbook/exercise-rendering-tree 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" "+e9271846294c4ee5bd7706df68180320c0b5ff20" "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 tiny-browserbook/exercise-rendering-tree against try#b69bfeecc49bf5661cf54497638430035ff61aa4 for pr-119820
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftiny-browserbook%2Fexercise-rendering-tree" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tiny-browserbook/exercise-rendering-tree on toolchain b69bfeecc49bf5661cf54497638430035ff61aa4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b69bfeecc49bf5661cf54497638430035ff61aa4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tiny-browserbook/exercise-rendering-tree
[INFO] finished tweaking git repo https://github.com/tiny-browserbook/exercise-rendering-tree
[INFO] tweaked toml for git repo https://github.com/tiny-browserbook/exercise-rendering-tree written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/tiny-browserbook/exercise-rendering-tree 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" "+b69bfeecc49bf5661cf54497638430035ff61aa4" "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-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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" "+b69bfeecc49bf5661cf54497638430035ff61aa4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 535d8ae881663501e1bf6e6b89d689abd2b7a2f34f23f6462e738d31a5c03e49
[INFO] running `Command { std: "docker" "start" "-a" "535d8ae881663501e1bf6e6b89d689abd2b7a2f34f23f6462e738d31a5c03e49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "535d8ae881663501e1bf6e6b89d689abd2b7a2f34f23f6462e738d31a5c03e49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "535d8ae881663501e1bf6e6b89d689abd2b7a2f34f23f6462e738d31a5c03e49", kill_on_drop: false }`
[INFO] [stdout] 535d8ae881663501e1bf6e6b89d689abd2b7a2f34f23f6462e738d31a5c03e49
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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" "+b69bfeecc49bf5661cf54497638430035ff61aa4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 74ec9763f912e6ef3686ac296f96e6acf76fef940b150465e8f5aae013e30ccd
[INFO] running `Command { std: "docker" "start" "-a" "74ec9763f912e6ef3686ac296f96e6acf76fef940b150465e8f5aae013e30ccd", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]     Checking combine v4.5.2
[INFO] [stderr]     Checking exercise-rendering-tree v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `NodeType`
[INFO] [stdout]  --> src/css.rs:9:24
[INFO] [stdout]   |
[INFO] [stdout] 9 | use crate::dom::{Node, NodeType};
[INFO] [stdout]   |                        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `NodeType`
[INFO] [stdout]  --> src/css.rs:9:24
[INFO] [stdout]   |
[INFO] [stdout] 9 | use crate::dom::{Node, NodeType};
[INFO] [stdout]   |                        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/css.rs:66:27
[INFO] [stdout]    |
[INFO] [stdout] 66 |     pub fn matches(&self, n: &Box<Node>) -> bool {
[INFO] [stdout]    |                           ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `node`
[INFO] [stdout]   --> src/style.rs:28:27
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub fn to_styled_node<'a>(node: &'a Box<Node>, stylesheet: &Stylesheet) -> Option<StyledNode<'a>> {
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_node`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stylesheet`
[INFO] [stdout]   --> src/style.rs:28:48
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub fn to_styled_node<'a>(node: &'a Box<Node>, stylesheet: &Stylesheet) -> Option<StyledNode<'a>> {
[INFO] [stdout]    |                                                ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_stylesheet`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `n`
[INFO] [stdout]   --> src/css.rs:66:27
[INFO] [stdout]    |
[INFO] [stdout] 66 |     pub fn matches(&self, n: &Box<Node>) -> bool {
[INFO] [stdout]    |                           ^ help: if this is intentional, prefix it with an underscore: `_n`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `node`
[INFO] [stdout]   --> src/style.rs:28:27
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub fn to_styled_node<'a>(node: &'a Box<Node>, stylesheet: &Stylesheet) -> Option<StyledNode<'a>> {
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_node`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `stylesheet`
[INFO] [stdout]   --> src/style.rs:28:48
[INFO] [stdout]    |
[INFO] [stdout] 28 | pub fn to_styled_node<'a>(node: &'a Box<Node>, stylesheet: &Stylesheet) -> Option<StyledNode<'a>> {
[INFO] [stdout]    |                                                ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_stylesheet`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.73s
[INFO] running `Command { std: "docker" "inspect" "74ec9763f912e6ef3686ac296f96e6acf76fef940b150465e8f5aae013e30ccd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "74ec9763f912e6ef3686ac296f96e6acf76fef940b150465e8f5aae013e30ccd", kill_on_drop: false }`
[INFO] [stdout] 74ec9763f912e6ef3686ac296f96e6acf76fef940b150465e8f5aae013e30ccd