[INFO] cloning repository https://github.com/benoitpas/rust-tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/benoitpas/rust-tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenoitpas%2Frust-tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenoitpas%2Frust-tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f94b1957ca04dac031c5261d60810a9c3b42e62f
[INFO] checking benoitpas/rust-tree against master#db1fb85cff63ad5fffe435e17128f99f9e1d970c for pr-89056
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenoitpas%2Frust-tree" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/benoitpas/rust-tree on toolchain db1fb85cff63ad5fffe435e17128f99f9e1d970c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/benoitpas/rust-tree
[INFO] finished tweaking git repo https://github.com/benoitpas/rust-tree
[INFO] tweaked toml for git repo https://github.com/benoitpas/rust-tree written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/benoitpas/rust-tree already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6f4acfde367a10d188e0a80fc3419f41fc58be71da5f107f8603ead418bc764c
[INFO] running `Command { std: "docker" "start" "-a" "6f4acfde367a10d188e0a80fc3419f41fc58be71da5f107f8603ead418bc764c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6f4acfde367a10d188e0a80fc3419f41fc58be71da5f107f8603ead418bc764c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f4acfde367a10d188e0a80fc3419f41fc58be71da5f107f8603ead418bc764c", kill_on_drop: false }`
[INFO] [stdout] 6f4acfde367a10d188e0a80fc3419f41fc58be71da5f107f8603ead418bc764c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2426f539ed912cf369535044be072708be6fd0217769de602f5fd36572041370
[INFO] running `Command { std: "docker" "start" "-a" "2426f539ed912cf369535044be072708be6fd0217769de602f5fd36572041370", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_tree v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: the method `to_string` exists for reference `&Display`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/lib.rs:28:57
[INFO] [stdout]    |
[INFO] [stdout] 28 |         Node::Branch(value, left, right) => "(" + value.to_string() + "," + to_string(left) + "," + to_string(right) + ")"
[INFO] [stdout]    |                                                         ^^^^^^^^^ method cannot be called on `&Display` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `Display: std::fmt::Display`
[INFO] [stdout]            which is required by `Display: ToString`
[INFO] [stdout]            `&Display: std::fmt::Display`
[INFO] [stdout]            which is required by `&Display: ToString`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_tree` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0599]: the method `to_string` exists for reference `&Display`, but its trait bounds were not satisfied
[INFO] [stdout]   --> src/lib.rs:28:57
[INFO] [stdout]    |
[INFO] [stdout] 28 |         Node::Branch(value, left, right) => "(" + value.to_string() + "," + to_string(left) + "," + to_string(right) + ")"
[INFO] [stdout]    |                                                         ^^^^^^^^^ method cannot be called on `&Display` due to unsatisfied trait bounds
[INFO] [stdout]    |
[INFO] [stdout]    = note: the following trait bounds were not satisfied:
[INFO] [stdout]            `Display: std::fmt::Display`
[INFO] [stdout]            which is required by `Display: ToString`
[INFO] [stdout]            `&Display: std::fmt::Display`
[INFO] [stdout]            which is required by `&Display: ToString`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2426f539ed912cf369535044be072708be6fd0217769de602f5fd36572041370", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2426f539ed912cf369535044be072708be6fd0217769de602f5fd36572041370", kill_on_drop: false }`
[INFO] [stdout] 2426f539ed912cf369535044be072708be6fd0217769de602f5fd36572041370