[INFO] fetching crate ziptree 0.1.1...
[INFO] testing ziptree-0.1.1 against 1.47.0 for beta-1.48-1
[INFO] extracting crate ziptree 0.1.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate ziptree 0.1.1 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ziptree 0.1.1
[INFO] finished tweaking crates.io crate ziptree 0.1.1
[INFO] tweaked toml for crates.io crate ziptree 0.1.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b9bce64b2c7ab8110ef5d7f7de6d1aed8d3a58a544814f5d04fdb13d842db91c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b9bce64b2c7ab8110ef5d7f7de6d1aed8d3a58a544814f5d04fdb13d842db91c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b9bce64b2c7ab8110ef5d7f7de6d1aed8d3a58a544814f5d04fdb13d842db91c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b9bce64b2c7ab8110ef5d7f7de6d1aed8d3a58a544814f5d04fdb13d842db91c", kill_on_drop: false }`
[INFO] [stdout] b9bce64b2c7ab8110ef5d7f7de6d1aed8d3a58a544814f5d04fdb13d842db91c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1939dab8214504e5480e6640bf25e7a6f3d8334d993947c5b99b9028d307196d
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "1939dab8214504e5480e6640bf25e7a6f3d8334d993947c5b99b9028d307196d", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling ziptree v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `greater`
[INFO] [stdout]    --> src/lib.rs:422:34
[INFO] [stdout]     |
[INFO] [stdout] 422 | ...                   Some(greater) => {
[INFO] [stdout]     |                            ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greater`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `less_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:372:25
[INFO] [stdout]     |
[INFO] [stdout] 370 |                     let node = less_nodes.back().unwrap();
[INFO] [stdout]     |                                ---------- immutable borrow occurs here
[INFO] [stdout] 371 |                     if !(**node).right.is_null() {
[INFO] [stdout] 372 |                         less_nodes.push_back((**node).right);
[INFO] [stdout]     |                         ^^^^^^^^^^           -------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `greater_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:386:25
[INFO] [stdout]     |
[INFO] [stdout] 384 |                     let node = greater_nodes.back().unwrap();
[INFO] [stdout]     |                                ------------- immutable borrow occurs here
[INFO] [stdout] 385 |                     if !(**node).left.is_null() {
[INFO] [stdout] 386 |                         greater_nodes.push_back((**node).left);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^           ------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:60:5
[INFO] [stdout]    |
[INFO] [stdout] 60 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `dump`
[INFO] [stdout]    --> src/lib.rs:534:8
[INFO] [stdout]     |
[INFO] [stdout] 534 |     fn dump(&self) where
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.79s
[INFO] running `Command { std: "docker" "inspect" "1939dab8214504e5480e6640bf25e7a6f3d8334d993947c5b99b9028d307196d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1939dab8214504e5480e6640bf25e7a6f3d8334d993947c5b99b9028d307196d", kill_on_drop: false }`
[INFO] [stdout] 1939dab8214504e5480e6640bf25e7a6f3d8334d993947c5b99b9028d307196d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ebf0550aa02c2a320e2ffda5d005e97c0186557946b8bbc207bdc8c7e0661a05
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "ebf0550aa02c2a320e2ffda5d005e97c0186557946b8bbc207bdc8c7e0661a05", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling ziptree v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `greater`
[INFO] [stdout]    --> src/lib.rs:422:34
[INFO] [stdout]     |
[INFO] [stdout] 422 | ...                   Some(greater) => {
[INFO] [stdout]     |                            ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greater`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `less_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:372:25
[INFO] [stdout]     |
[INFO] [stdout] 370 |                     let node = less_nodes.back().unwrap();
[INFO] [stdout]     |                                ---------- immutable borrow occurs here
[INFO] [stdout] 371 |                     if !(**node).right.is_null() {
[INFO] [stdout] 372 |                         less_nodes.push_back((**node).right);
[INFO] [stdout]     |                         ^^^^^^^^^^           -------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `greater_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:386:25
[INFO] [stdout]     |
[INFO] [stdout] 384 |                     let node = greater_nodes.back().unwrap();
[INFO] [stdout]     |                                ------------- immutable borrow occurs here
[INFO] [stdout] 385 |                     if !(**node).left.is_null() {
[INFO] [stdout] 386 |                         greater_nodes.push_back((**node).left);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^           ------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:60:5
[INFO] [stdout]    |
[INFO] [stdout] 60 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `dump`
[INFO] [stdout]    --> src/lib.rs:534:8
[INFO] [stdout]     |
[INFO] [stdout] 534 |     fn dump(&self) where
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `HashMap`
[INFO] [stdout]  --> tests/simple.rs:2:24
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::collections::{HashMap, BTreeMap};
[INFO] [stdout]   |                        ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `greater`
[INFO] [stdout]    --> src/lib.rs:422:34
[INFO] [stdout]     |
[INFO] [stdout] 422 | ...                   Some(greater) => {
[INFO] [stdout]     |                            ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greater`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `less_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:372:25
[INFO] [stdout]     |
[INFO] [stdout] 370 |                     let node = less_nodes.back().unwrap();
[INFO] [stdout]     |                                ---------- immutable borrow occurs here
[INFO] [stdout] 371 |                     if !(**node).right.is_null() {
[INFO] [stdout] 372 |                         less_nodes.push_back((**node).right);
[INFO] [stdout]     |                         ^^^^^^^^^^           -------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: cannot borrow `greater_nodes` as mutable because it is also borrowed as immutable
[INFO] [stdout]    --> src/lib.rs:386:25
[INFO] [stdout]     |
[INFO] [stdout] 384 |                     let node = greater_nodes.back().unwrap();
[INFO] [stdout]     |                                ------------- immutable borrow occurs here
[INFO] [stdout] 385 |                     if !(**node).left.is_null() {
[INFO] [stdout] 386 |                         greater_nodes.push_back((**node).left);
[INFO] [stdout]     |                         ^^^^^^^^^^^^^           ------------- immutable borrow later used here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         mutable borrow occurs here
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stdout]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `tree`
[INFO] [stdout]   --> src/lib.rs:60:5
[INFO] [stdout]    |
[INFO] [stdout] 60 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `dump`
[INFO] [stdout]    --> src/lib.rs:534:8
[INFO] [stdout]     |
[INFO] [stdout] 534 |     fn dump(&self) where
[INFO] [stdout]     |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 2.32s
[INFO] running `Command { std: "docker" "inspect" "ebf0550aa02c2a320e2ffda5d005e97c0186557946b8bbc207bdc8c7e0661a05", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ebf0550aa02c2a320e2ffda5d005e97c0186557946b8bbc207bdc8c7e0661a05", kill_on_drop: false }`
[INFO] [stdout] ebf0550aa02c2a320e2ffda5d005e97c0186557946b8bbc207bdc8c7e0661a05
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 5fb8069e063388506cf920706b3dc9bad7a0e521db2d939fabe862871d1dc6b7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "5fb8069e063388506cf920706b3dc9bad7a0e521db2d939fabe862871d1dc6b7", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] warning: unused variable: `greater`
[INFO] [stderr]    --> src/lib.rs:422:34
[INFO] [stderr]     |
[INFO] [stderr] 422 | ...                   Some(greater) => {
[INFO] [stderr]     |                            ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greater`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: cannot borrow `less_nodes` as mutable because it is also borrowed as immutable
[INFO] [stderr]    --> src/lib.rs:372:25
[INFO] [stderr]     |
[INFO] [stderr] 370 |                     let node = less_nodes.back().unwrap();
[INFO] [stderr]     |                                ---------- immutable borrow occurs here
[INFO] [stderr] 371 |                     if !(**node).right.is_null() {
[INFO] [stderr] 372 |                         less_nodes.push_back((**node).right);
[INFO] [stderr]     |                         ^^^^^^^^^^           -------------- immutable borrow later used here
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         mutable borrow occurs here
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stderr]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stderr]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stderr] 
[INFO] [stderr] warning: cannot borrow `greater_nodes` as mutable because it is also borrowed as immutable
[INFO] [stderr]    --> src/lib.rs:386:25
[INFO] [stderr]     |
[INFO] [stderr] 384 |                     let node = greater_nodes.back().unwrap();
[INFO] [stderr]     |                                ------------- immutable borrow occurs here
[INFO] [stderr] 385 |                     if !(**node).left.is_null() {
[INFO] [stderr] 386 |                         greater_nodes.push_back((**node).left);
[INFO] [stderr]     |                         ^^^^^^^^^^^^^           ------------- immutable borrow later used here
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         mutable borrow occurs here
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stderr]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `tree`
[INFO] [stderr]   --> src/lib.rs:37:5
[INFO] [stderr]    |
[INFO] [stderr] 37 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `tree`
[INFO] [stderr]   --> src/lib.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `dump`
[INFO] [stderr]    --> src/lib.rs:534:8
[INFO] [stderr]     |
[INFO] [stderr] 534 |     fn dump(&self) where
[INFO] [stderr]     |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 6 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `greater`
[INFO] [stderr]    --> src/lib.rs:422:34
[INFO] [stderr]     |
[INFO] [stderr] 422 | ...                   Some(greater) => {
[INFO] [stderr]     |                            ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_greater`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: cannot borrow `less_nodes` as mutable because it is also borrowed as immutable
[INFO] [stderr]    --> src/lib.rs:372:25
[INFO] [stderr]     |
[INFO] [stderr] 370 |                     let node = less_nodes.back().unwrap();
[INFO] [stderr]     |                                ---------- immutable borrow occurs here
[INFO] [stderr] 371 |                     if !(**node).right.is_null() {
[INFO] [stderr] 372 |                         less_nodes.push_back((**node).right);
[INFO] [stderr]     |                         ^^^^^^^^^^           -------------- immutable borrow later used here
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         mutable borrow occurs here
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(mutable_borrow_reservation_conflict)]` on by default
[INFO] [stderr]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stderr]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stderr] 
[INFO] [stderr] warning: cannot borrow `greater_nodes` as mutable because it is also borrowed as immutable
[INFO] [stderr]    --> src/lib.rs:386:25
[INFO] [stderr]     |
[INFO] [stderr] 384 |                     let node = greater_nodes.back().unwrap();
[INFO] [stderr]     |                                ------------- immutable borrow occurs here
[INFO] [stderr] 385 |                     if !(**node).left.is_null() {
[INFO] [stderr] 386 |                         greater_nodes.push_back((**node).left);
[INFO] [stderr]     |                         ^^^^^^^^^^^^^           ------------- immutable borrow later used here
[INFO] [stderr]     |                         |
[INFO] [stderr]     |                         mutable borrow occurs here
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
[INFO] [stderr]     = note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `tree`
[INFO] [stderr]   --> src/lib.rs:37:5
[INFO] [stderr]    |
[INFO] [stderr] 37 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `tree`
[INFO] [stderr]   --> src/lib.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     tree: &'a mut ZipTree<K, V>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `dump`
[INFO] [stderr]    --> src/lib.rs:534:8
[INFO] [stderr]     |
[INFO] [stderr] 534 |     fn dump(&self) where
[INFO] [stderr]     |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 6 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `HashMap`
[INFO] [stderr]  --> tests/simple.rs:2:24
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::collections::{HashMap, BTreeMap};
[INFO] [stderr]   |                        ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.11s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/ziptree-cf771ab1facf2e05
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/simple-53dfe805922aaaa4
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test simple_test ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests ziptree
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "5fb8069e063388506cf920706b3dc9bad7a0e521db2d939fabe862871d1dc6b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fb8069e063388506cf920706b3dc9bad7a0e521db2d939fabe862871d1dc6b7", kill_on_drop: false }`
[INFO] [stdout] 5fb8069e063388506cf920706b3dc9bad7a0e521db2d939fabe862871d1dc6b7
