[INFO] cloning repository https://github.com/myself659/avltree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/myself659/avltree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmyself659%2Favltree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmyself659%2Favltree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2408a6a6eadad2c48086268f33aba7039affcde8
[INFO] checking myself659/avltree against try#012cd62c9add58ab3910e44c137d87db3ab70f61 for pr-155915
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmyself659%2Favltree" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/myself659/avltree
[INFO] finished tweaking git repo https://github.com/myself659/avltree
[INFO] tweaked toml for git repo https://github.com/myself659/avltree written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/myself659/avltree on toolchain 012cd62c9add58ab3910e44c137d87db3ab70f61
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+012cd62c9add58ab3910e44c137d87db3ab70f61" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/myself659/avltree 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" "+012cd62c9add58ab3910e44c137d87db3ab70f61" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+012cd62c9add58ab3910e44c137d87db3ab70f61" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ba75665c2b7b1e9e503b48760bede10a4fe564f4d50881364d57747ad629bee9
[INFO] running `Command { std: "docker" "start" "-a" "ba75665c2b7b1e9e503b48760bede10a4fe564f4d50881364d57747ad629bee9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ba75665c2b7b1e9e503b48760bede10a4fe564f4d50881364d57747ad629bee9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba75665c2b7b1e9e503b48760bede10a4fe564f4d50881364d57747ad629bee9", kill_on_drop: false }`
[INFO] [stdout] ba75665c2b7b1e9e503b48760bede10a4fe564f4d50881364d57747ad629bee9
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+012cd62c9add58ab3910e44c137d87db3ab70f61" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 864d0323ba9579cffb78bcaf3cba0b5dd0195ec312e7a11ba1b4e45265b34f39
[INFO] running `Command { std: "docker" "start" "-a" "864d0323ba9579cffb78bcaf3cba0b5dd0195ec312e7a11ba1b4e45265b34f39", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v0.1.5
[INFO] [stderr]    Compiling libc v0.2.61
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking either v1.5.2
[INFO] [stderr]     Checking avltree v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking env_logger v0.6.2
[INFO] [stderr]     Checking itertools v0.8.0
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/set.rs:118:17
[INFO] [stdout]     |
[INFO] [stdout] 118 |                 replace(&mut target_node.right, right_node.right.take());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 118 |                 let _ = replace(&mut target_node.right, right_node.right.take());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/set.rs:139:17
[INFO] [stdout]     |
[INFO] [stdout] 139 |                 replace(&mut parent_left_node.left, leftmost_node.right.take());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 139 |                 let _ = replace(&mut parent_left_node.left, leftmost_node.right.take());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking quickcheck v0.8.5
[INFO] [stderr]    Compiling quickcheck_macros v0.8.0
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/set.rs:118:17
[INFO] [stdout]     |
[INFO] [stdout] 118 |                 replace(&mut target_node.right, right_node.right.take());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 118 |                 let _ = replace(&mut target_node.right, right_node.right.take());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/set.rs:139:17
[INFO] [stdout]     |
[INFO] [stdout] 139 |                 replace(&mut parent_left_node.left, leftmost_node.right.take());
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 139 |                 let _ = replace(&mut parent_left_node.left, leftmost_node.right.take());
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.72s
[INFO] running `Command { std: "docker" "inspect" "864d0323ba9579cffb78bcaf3cba0b5dd0195ec312e7a11ba1b4e45265b34f39", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "864d0323ba9579cffb78bcaf3cba0b5dd0195ec312e7a11ba1b4e45265b34f39", kill_on_drop: false }`
[INFO] [stdout] 864d0323ba9579cffb78bcaf3cba0b5dd0195ec312e7a11ba1b4e45265b34f39
