[INFO] crate disjoint-set 0.0.2 is already in cache [INFO] testing disjoint-set-0.0.2 against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409 [INFO] extracting crate disjoint-set 0.0.2 into /workspace/builds/worker-4/source [INFO] validating manifest of crates.io crate disjoint-set 0.0.2 on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] started tweaking crates.io crate disjoint-set 0.0.2 [INFO] finished tweaking crates.io crate disjoint-set 0.0.2 [INFO] tweaked toml for crates.io crate disjoint-set 0.0.2 written to /workspace/builds/worker-4/source/Cargo.toml [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }` [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 4c2b8d4589aa4755ce667a5fb7e1413fd69a586585c56c6e26732bd1c46896e9 [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" "4c2b8d4589aa4755ce667a5fb7e1413fd69a586585c56c6e26732bd1c46896e9", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "4c2b8d4589aa4755ce667a5fb7e1413fd69a586585c56c6e26732bd1c46896e9", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "4c2b8d4589aa4755ce667a5fb7e1413fd69a586585c56c6e26732bd1c46896e9", kill_on_drop: false }` [INFO] [stdout] 4c2b8d4589aa4755ce667a5fb7e1413fd69a586585c56c6e26732bd1c46896e9 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 74d04993419579eeef3680c7565bca7fb873e46b31690e5241aefd62ad3d0db8 [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" "74d04993419579eeef3680c7565bca7fb873e46b31690e5241aefd62ad3d0db8", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Compiling disjoint-set v0.0.2 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused import: `std::rc::Rc` [INFO] [stdout] --> src/lib.rs:3:5 [INFO] [stdout] | [INFO] [stdout] 3 | use std::rc::Rc; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `p` [INFO] [stdout] --> src/lib.rs:37:18 [INFO] [stdout] | [INFO] [stdout] 37 | Some(p) => return, [INFO] [stdout] | ^ help: if this is intentional, prefix it with an underscore: `_p` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:35:13 [INFO] [stdout] | [INFO] [stdout] 35 | let mut len = &mut self.set_size; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_mut)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:53:13 [INFO] [stdout] | [INFO] [stdout] 53 | let mut pos: usize; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Root` [INFO] [stdout] --> src/lib.rs:7:5 [INFO] [stdout] | [INFO] [stdout] 7 | Root(ValueType, u32), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Link` [INFO] [stdout] --> src/lib.rs:8:5 [INFO] [stdout] | [INFO] [stdout] 8 | Link(Box>) [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 0.63s [INFO] running `Command { std: "docker" "inspect" "74d04993419579eeef3680c7565bca7fb873e46b31690e5241aefd62ad3d0db8", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "74d04993419579eeef3680c7565bca7fb873e46b31690e5241aefd62ad3d0db8", kill_on_drop: false }` [INFO] [stdout] 74d04993419579eeef3680c7565bca7fb873e46b31690e5241aefd62ad3d0db8 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 5025ec6180f839a909215b43c5382d3a4b264234ce66b6b1a6e8fb2c9bf0aeb9 [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" "5025ec6180f839a909215b43c5382d3a4b264234ce66b6b1a6e8fb2c9bf0aeb9", kill_on_drop: false }` [INFO] [stdout] warning: unused import: `std::rc::Rc` [INFO] [stdout] --> src/lib.rs:3:5 [INFO] [stdout] | [INFO] [stdout] 3 | use std::rc::Rc; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Compiling disjoint-set v0.0.2 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused variable: `p` [INFO] [stdout] --> src/lib.rs:37:18 [INFO] [stdout] | [INFO] [stdout] 37 | Some(p) => return, [INFO] [stdout] | ^ help: if this is intentional, prefix it with an underscore: `_p` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:35:13 [INFO] [stdout] | [INFO] [stdout] 35 | let mut len = &mut self.set_size; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_mut)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:53:13 [INFO] [stdout] | [INFO] [stdout] 53 | let mut pos: usize; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Root` [INFO] [stdout] --> src/lib.rs:7:5 [INFO] [stdout] | [INFO] [stdout] 7 | Root(ValueType, u32), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Link` [INFO] [stdout] --> src/lib.rs:8:5 [INFO] [stdout] | [INFO] [stdout] 8 | Link(Box>) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: 6 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused import: `std::rc::Rc` [INFO] [stdout] --> src/lib.rs:3:5 [INFO] [stdout] | [INFO] [stdout] 3 | use std::rc::Rc; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `p` [INFO] [stdout] --> src/lib.rs:37:18 [INFO] [stdout] | [INFO] [stdout] 37 | Some(p) => return, [INFO] [stdout] | ^ help: if this is intentional, prefix it with an underscore: `_p` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:35:13 [INFO] [stdout] | [INFO] [stdout] 35 | let mut len = &mut self.set_size; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_mut)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable does not need to be mutable [INFO] [stdout] --> src/lib.rs:53:13 [INFO] [stdout] | [INFO] [stdout] 53 | let mut pos: usize; [INFO] [stdout] | ----^^^ [INFO] [stdout] | | [INFO] [stdout] | help: remove this `mut` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Root` [INFO] [stdout] --> src/lib.rs:7:5 [INFO] [stdout] | [INFO] [stdout] 7 | Root(ValueType, u32), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant is never constructed: `Link` [INFO] [stdout] --> src/lib.rs:8:5 [INFO] [stdout] | [INFO] [stdout] 8 | Link(Box>) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `std::result::Result` that must be used [INFO] [stdout] --> src/lib.rs:106:5 [INFO] [stdout] | [INFO] [stdout] 106 | ds.union(1, 2); [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_must_use)]` on by default [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `std::result::Result` that must be used [INFO] [stdout] --> src/lib.rs:107:5 [INFO] [stdout] | [INFO] [stdout] 107 | ds.union(2, 3); [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `std::result::Result` that must be used [INFO] [stdout] --> src/lib.rs:118:5 [INFO] [stdout] | [INFO] [stdout] 118 | ds.union(-1, 4); [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused `std::result::Result` that must be used [INFO] [stdout] --> src/lib.rs:119:5 [INFO] [stdout] | [INFO] [stdout] 119 | ds.union(2, 4); [INFO] [stdout] | ^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: 10 warnings emitted [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 1.01s [INFO] running `Command { std: "docker" "inspect" "5025ec6180f839a909215b43c5382d3a4b264234ce66b6b1a6e8fb2c9bf0aeb9", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "5025ec6180f839a909215b43c5382d3a4b264234ce66b6b1a6e8fb2c9bf0aeb9", kill_on_drop: false }` [INFO] [stdout] 5025ec6180f839a909215b43c5382d3a4b264234ce66b6b1a6e8fb2c9bf0aeb9 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "test" "--frozen", kill_on_drop: false }` [INFO] [stdout] c061a40c4c1da6f30f89837302f561b2aff4e87300e1f0ad8ae8a064ac488ff4 [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" "c061a40c4c1da6f30f89837302f561b2aff4e87300e1f0ad8ae8a064ac488ff4", kill_on_drop: false }` [INFO] [stderr] warning: unused import: `std::rc::Rc` [INFO] [stderr] --> src/lib.rs:3:5 [INFO] [stderr] | [INFO] [stderr] 3 | use std::rc::Rc; [INFO] [stderr] | ^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_imports)]` on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `p` [INFO] [stderr] --> src/lib.rs:37:18 [INFO] [stderr] | [INFO] [stderr] 37 | Some(p) => return, [INFO] [stderr] | ^ help: if this is intentional, prefix it with an underscore: `_p` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_variables)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/lib.rs:35:13 [INFO] [stderr] | [INFO] [stderr] 35 | let mut len = &mut self.set_size; [INFO] [stderr] | ----^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this `mut` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_mut)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/lib.rs:53:13 [INFO] [stderr] | [INFO] [stderr] 53 | let mut pos: usize; [INFO] [stderr] | ----^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this `mut` [INFO] [stderr] [INFO] [stderr] warning: variant is never constructed: `Root` [INFO] [stderr] --> src/lib.rs:7:5 [INFO] [stderr] | [INFO] [stderr] 7 | Root(ValueType, u32), [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(dead_code)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variant is never constructed: `Link` [INFO] [stderr] --> src/lib.rs:8:5 [INFO] [stderr] | [INFO] [stderr] 8 | Link(Box>) [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] [INFO] [stderr] warning: 6 warnings emitted [INFO] [stderr] [INFO] [stderr] warning: unused import: `std::rc::Rc` [INFO] [stderr] --> src/lib.rs:3:5 [INFO] [stderr] | [INFO] [stderr] 3 | use std::rc::Rc; [INFO] [stderr] | ^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_imports)]` on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `p` [INFO] [stderr] --> src/lib.rs:37:18 [INFO] [stderr] | [INFO] [stderr] 37 | Some(p) => return, [INFO] [stderr] | ^ help: if this is intentional, prefix it with an underscore: `_p` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_variables)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/lib.rs:35:13 [INFO] [stderr] | [INFO] [stderr] 35 | let mut len = &mut self.set_size; [INFO] [stderr] | ----^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this `mut` [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_mut)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/lib.rs:53:13 [INFO] [stderr] | [INFO] [stderr] 53 | let mut pos: usize; [INFO] [stderr] | ----^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this `mut` [INFO] [stderr] [INFO] [stderr] warning: variant is never constructed: `Root` [INFO] [stderr] --> src/lib.rs:7:5 [INFO] [stderr] | [INFO] [stderr] 7 | Root(ValueType, u32), [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(dead_code)]` on by default [INFO] [stderr] [INFO] [stderr] warning: variant is never constructed: `Link` [INFO] [stderr] --> src/lib.rs:8:5 [INFO] [stderr] | [INFO] [stderr] 8 | Link(Box>) [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/lib.rs:106:5 [INFO] [stderr] | [INFO] [stderr] 106 | ds.union(1, 2); [INFO] [stderr] | ^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: `#[warn(unused_must_use)]` on by default [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/lib.rs:107:5 [INFO] [stderr] | [INFO] [stderr] 107 | ds.union(2, 3); [INFO] [stderr] | ^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/lib.rs:118:5 [INFO] [stderr] | [INFO] [stderr] 118 | ds.union(-1, 4); [INFO] [stderr] | ^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/lib.rs:119:5 [INFO] [stderr] | [INFO] [stderr] 119 | ds.union(2, 4); [INFO] [stderr] | ^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: 10 warnings emitted [INFO] [stderr] [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 0.06s [INFO] [stderr] Running /opt/rustwide/target/debug/deps/disjoint_set-6b02238ed15fe9ef [INFO] [stdout] [INFO] [stderr] Doc-tests disjoint-set [INFO] [stdout] running 1 test [INFO] [stdout] test it_works ... ok [INFO] [stdout] [INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [INFO] [stdout] [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" "c061a40c4c1da6f30f89837302f561b2aff4e87300e1f0ad8ae8a064ac488ff4", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "c061a40c4c1da6f30f89837302f561b2aff4e87300e1f0ad8ae8a064ac488ff4", kill_on_drop: false }` [INFO] [stdout] c061a40c4c1da6f30f89837302f561b2aff4e87300e1f0ad8ae8a064ac488ff4