[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#b1f2594eac607c1f051534800237eeedb5590a49 for pr-139493-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmyself659%2Favltree" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-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-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/myself659/avltree on toolchain b1f2594eac607c1f051534800237eeedb5590a49
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "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" "+b1f2594eac607c1f051534800237eeedb5590a49" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e37794bc9df0a51dedc066c61f9b7d47dbf38d96f07c0fe47e867b9a875d1447
[INFO] running `Command { std: "docker" "start" "-a" "e37794bc9df0a51dedc066c61f9b7d47dbf38d96f07c0fe47e867b9a875d1447", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e37794bc9df0a51dedc066c61f9b7d47dbf38d96f07c0fe47e867b9a875d1447", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e37794bc9df0a51dedc066c61f9b7d47dbf38d96f07c0fe47e867b9a875d1447", kill_on_drop: false }`
[INFO] [stdout] e37794bc9df0a51dedc066c61f9b7d47dbf38d96f07c0fe47e867b9a875d1447
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:aa71247004a7fa38d13ec170f48f06cdedf5bc50b2a8645e56ed7e992e6fa513" "/opt/rustwide/cargo-home/bin/cargo" "+b1f2594eac607c1f051534800237eeedb5590a49" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e8bb2a02cc0bd99b1f78558b77c39073bed5967623310ca2b5200b7d91aa4564
[INFO] running `Command { std: "docker" "start" "-a" "e8bb2a02cc0bd99b1f78558b77c39073bed5967623310ca2b5200b7d91aa4564", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.61
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking regex-syntax v0.6.11
[INFO] [stderr]     Checking cfg-if v0.1.9
[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 log v0.4.8
[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]     Checking itertools v0.8.0
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking regex v1.2.1
[INFO] [stderr]     Checking env_logger v0.6.2
[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 6.76s
[INFO] running `Command { std: "docker" "inspect" "e8bb2a02cc0bd99b1f78558b77c39073bed5967623310ca2b5200b7d91aa4564", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8bb2a02cc0bd99b1f78558b77c39073bed5967623310ca2b5200b7d91aa4564", kill_on_drop: false }`
[INFO] [stdout] e8bb2a02cc0bd99b1f78558b77c39073bed5967623310ca2b5200b7d91aa4564