[INFO] fetching crate segmap 0.1.0...
[INFO] building segmap-0.1.0 against try#4987e9d4227139400384ab59296ffee3b0fb1183 for pr-146237-2
[INFO] extracting crate segmap 0.1.0 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate segmap 0.1.0
[INFO] finished tweaking crates.io crate segmap 0.1.0
[INFO] tweaked toml for crates.io crate segmap 0.1.0 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate segmap 0.1.0 on toolchain 4987e9d4227139400384ab59296ffee3b0fb1183
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate segmap 0.1.0 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" "+4987e9d4227139400384ab59296ffee3b0fb1183" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b134ab652351137f42bdb378d09e890b713bcc35a04ec8cb922c5d947b8d049c
[INFO] running `Command { std: "docker" "start" "-a" "b134ab652351137f42bdb378d09e890b713bcc35a04ec8cb922c5d947b8d049c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b134ab652351137f42bdb378d09e890b713bcc35a04ec8cb922c5d947b8d049c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b134ab652351137f42bdb378d09e890b713bcc35a04ec8cb922c5d947b8d049c", kill_on_drop: false }`
[INFO] [stdout] b134ab652351137f42bdb378d09e890b713bcc35a04ec8cb922c5d947b8d049c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 422722fcb4c3d02a980f7a8fe3fcadd3220d325344e326db7821cd1326a88afe
[INFO] running `Command { std: "docker" "start" "-a" "422722fcb4c3d02a980f7a8fe3fcadd3220d325344e326db7821cd1326a88afe", kill_on_drop: false }`
[INFO] [stderr]    Compiling segmap v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:168:29
[INFO] [stdout]     |
[INFO] [stdout] 168 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[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] 168 |                             let _ = prev_other.insert(other);
[INFO] [stdout]     |                             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:128:17
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 self.prev_b.insert(next_b);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:701:21
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     let _ = self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]   --> src/set/ops/union.rs:98:13
[INFO] [stdout]    |
[INFO] [stdout] 98 |             self.prev_b.insert(next_b);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 98 |             let _ = self.prev_b.insert(next_b);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:723:25
[INFO] [stdout]     |
[INFO] [stdout] 723 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 724 | |                             before: None,
[INFO] [stdout] 725 | |                             iter,
[INFO] [stdout] 726 | |                             range,
[INFO] [stdout] 727 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 723 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:746:25
[INFO] [stdout]     |
[INFO] [stdout] 746 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 747 | |                             before: None,
[INFO] [stdout] 748 | |                             iter,
[INFO] [stdout] 749 | |                             range,
[INFO] [stdout] 750 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 746 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:781:13
[INFO] [stdout]     |
[INFO] [stdout] 781 |             self.prev.insert(next);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 781 |             let _ = self.prev.insert(next);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:834:21
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:845:21
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:138:21
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:146:21
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:157:21
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:178:21
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:134:17
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 self.prev_a.insert(next_a);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:150:21
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 | /                     self.prev_a.insert(Segment {
[INFO] [stdout] 166 | |                         start: next_b.borrow_bound_after().unwrap(),
[INFO] [stdout] 167 | |                         end: next_a.end,
[INFO] [stdout] 168 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_a.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:220:21
[INFO] [stdout]     |
[INFO] [stdout] 220 | /                     self.prev_b.insert(Segment {
[INFO] [stdout] 221 | |                         start: next_a.borrow_bound_after().unwrap(),
[INFO] [stdout] 222 | |                         end: next_b.end,
[INFO] [stdout] 223 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 220 |                     let _ = self.prev_b.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:245:21
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:188:33
[INFO] [stdout]     |
[INFO] [stdout] 188 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 188 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:203:33
[INFO] [stdout]     |
[INFO] [stdout] 203 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 203 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:225:33
[INFO] [stdout]     |
[INFO] [stdout] 225 | / ...                   prev_self.insert(Segment {
[INFO] [stdout] 226 | | ...                       start: other.borrow_bound_after().unwrap(),
[INFO] [stdout] 227 | | ...                       end: core::mem::replace(
[INFO] [stdout] 228 | | ...                           &mut range.end,
[INFO] [stdout] 229 | | ...                           other.borrow_bound_before().unwrap(),
[INFO] [stdout] 230 | | ...                       ),
[INFO] [stdout] 231 | | ...                   });
[INFO] [stdout]     | |________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 225 |                                 let _ = prev_self.insert(Segment {
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |             self.prev_a.insert(next_a);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_a.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_a.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:142:21
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     self.prev_b.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     let _ = self.prev_b.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.67s
[INFO] running `Command { std: "docker" "inspect" "422722fcb4c3d02a980f7a8fe3fcadd3220d325344e326db7821cd1326a88afe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "422722fcb4c3d02a980f7a8fe3fcadd3220d325344e326db7821cd1326a88afe", kill_on_drop: false }`
[INFO] [stdout] 422722fcb4c3d02a980f7a8fe3fcadd3220d325344e326db7821cd1326a88afe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+4987e9d4227139400384ab59296ffee3b0fb1183" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fba00561d168eef47d1500f9a1d020e0de1ab9cbb97ec52313d358c7b4d3e02f
[INFO] running `Command { std: "docker" "start" "-a" "fba00561d168eef47d1500f9a1d020e0de1ab9cbb97ec52313d358c7b4d3e02f", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling semver v1.0.3
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling itoa v0.4.7
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]    Compiling plotters-backend v0.3.2
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling regex-automata v0.1.10
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling half v1.7.1
[INFO] [stderr]    Compiling itertools v0.9.0
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling plotters-svg v0.3.1
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling itertools v0.10.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling rustc_version v0.4.0
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling crossbeam-channel v0.5.1
[INFO] [stderr]    Compiling cast v0.2.7
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling walkdir v2.3.2
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling oorandom v11.1.3
[INFO] [stderr]    Compiling rangemap v0.1.11
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:168:29
[INFO] [stdout]     |
[INFO] [stdout] 168 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[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] 168 |                             let _ = prev_other.insert(other);
[INFO] [stdout]     |                             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:128:17
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 self.prev_b.insert(next_b);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:701:21
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     let _ = self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]   --> src/set/ops/union.rs:98:13
[INFO] [stdout]    |
[INFO] [stdout] 98 |             self.prev_b.insert(next_b);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 98 |             let _ = self.prev_b.insert(next_b);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:723:25
[INFO] [stdout]     |
[INFO] [stdout] 723 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 724 | |                             before: None,
[INFO] [stdout] 725 | |                             iter,
[INFO] [stdout] 726 | |                             range,
[INFO] [stdout] 727 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 723 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:746:25
[INFO] [stdout]     |
[INFO] [stdout] 746 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 747 | |                             before: None,
[INFO] [stdout] 748 | |                             iter,
[INFO] [stdout] 749 | |                             range,
[INFO] [stdout] 750 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 746 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:781:13
[INFO] [stdout]     |
[INFO] [stdout] 781 |             self.prev.insert(next);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 781 |             let _ = self.prev.insert(next);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:834:21
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:845:21
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:138:21
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:146:21
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:157:21
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:178:21
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:134:17
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 self.prev_a.insert(next_a);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:150:21
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 | /                     self.prev_a.insert(Segment {
[INFO] [stdout] 166 | |                         start: next_b.borrow_bound_after().unwrap(),
[INFO] [stdout] 167 | |                         end: next_a.end,
[INFO] [stdout] 168 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_a.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:220:21
[INFO] [stdout]     |
[INFO] [stdout] 220 | /                     self.prev_b.insert(Segment {
[INFO] [stdout] 221 | |                         start: next_a.borrow_bound_after().unwrap(),
[INFO] [stdout] 222 | |                         end: next_b.end,
[INFO] [stdout] 223 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 220 |                     let _ = self.prev_b.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:245:21
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:188:33
[INFO] [stdout]     |
[INFO] [stdout] 188 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 188 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:203:33
[INFO] [stdout]     |
[INFO] [stdout] 203 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 203 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:225:33
[INFO] [stdout]     |
[INFO] [stdout] 225 | / ...                   prev_self.insert(Segment {
[INFO] [stdout] 226 | | ...                       start: other.borrow_bound_after().unwrap(),
[INFO] [stdout] 227 | | ...                       end: core::mem::replace(
[INFO] [stdout] 228 | | ...                           &mut range.end,
[INFO] [stdout] 229 | | ...                           other.borrow_bound_before().unwrap(),
[INFO] [stdout] 230 | | ...                       ),
[INFO] [stdout] 231 | | ...                   });
[INFO] [stdout]     | |________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 225 |                                 let _ = prev_self.insert(Segment {
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |             self.prev_a.insert(next_a);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_a.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_a.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:142:21
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     self.prev_b.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     let _ = self.prev_b.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling criterion-plot v0.4.3
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling bstr v0.2.16
[INFO] [stderr]    Compiling serde_cbor v0.11.1
[INFO] [stderr]    Compiling plotters v0.3.1
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling tinytemplate v1.2.1
[INFO] [stderr]    Compiling csv v1.1.6
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling permutator v0.4.0
[INFO] [stderr]    Compiling criterion v0.3.4
[INFO] [stderr]    Compiling segmap v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]   --> src/set/ops/union.rs:98:13
[INFO] [stdout]    |
[INFO] [stdout] 98 |             self.prev_b.insert(next_b);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you intended to set a value, consider assignment instead
[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] 98 |             let _ = self.prev_b.insert(next_b);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:168:29
[INFO] [stdout]     |
[INFO] [stdout] 168 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 168 |                             let _ = prev_other.insert(other);
[INFO] [stdout]     |                             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:188:33
[INFO] [stdout]     |
[INFO] [stdout] 188 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 188 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:203:33
[INFO] [stdout]     |
[INFO] [stdout] 203 | ...                   prev_other.insert(other);
[INFO] [stdout]     |                       ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 203 |                                 let _ = prev_other.insert(other);
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/difference.rs:225:33
[INFO] [stdout]     |
[INFO] [stdout] 225 | / ...                   prev_self.insert(Segment {
[INFO] [stdout] 226 | | ...                       start: other.borrow_bound_after().unwrap(),
[INFO] [stdout] 227 | | ...                       end: core::mem::replace(
[INFO] [stdout] 228 | | ...                           &mut range.end,
[INFO] [stdout] 229 | | ...                           other.borrow_bound_before().unwrap(),
[INFO] [stdout] 230 | | ...                       ),
[INFO] [stdout] 231 | | ...                   });
[INFO] [stdout]     | |________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 225 |                                 let _ = prev_self.insert(Segment {
[INFO] [stdout]     |                                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:138:21
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 138 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:146:21
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 146 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:157:21
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 157 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/intersection.rs:178:21
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 178 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:104:13
[INFO] [stdout]     |
[INFO] [stdout] 104 |             self.prev_a.insert(next_a);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:126:21
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     self.prev_a.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 126 |                     let _ = self.prev_a.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/union.rs:142:21
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     self.prev_b.insert(r);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 142 |                     let _ = self.prev_b.insert(r);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:701:21
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 701 |                     let _ = self.0.insert(IterSubsetInner::Full(iter));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:723:25
[INFO] [stdout]     |
[INFO] [stdout] 723 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 724 | |                             before: None,
[INFO] [stdout] 725 | |                             iter,
[INFO] [stdout] 726 | |                             range,
[INFO] [stdout] 727 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 723 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:746:25
[INFO] [stdout]     |
[INFO] [stdout] 746 | /                         self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout] 747 | |                             before: None,
[INFO] [stdout] 748 | |                             iter,
[INFO] [stdout] 749 | |                             range,
[INFO] [stdout] 750 | |                         });
[INFO] [stdout]     | |__________________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 746 |                         let _ = self.0.insert(IterSubsetInner::Partial {
[INFO] [stdout]     |                         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:781:13
[INFO] [stdout]     |
[INFO] [stdout] 781 |             self.prev.insert(next);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 781 |             let _ = self.prev.insert(next);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:834:21
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 834 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/map/iterators.rs:845:21
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 845 |                     let _ = self.0.insert(ComplementInner::Gaps(gaps));
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:128:17
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 self.prev_b.insert(next_b);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 128 |                 let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:134:17
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 self.prev_a.insert(next_a);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 134 |                 let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:150:21
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     self.prev_b.insert(next_b);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 150 |                     let _ = self.prev_b.insert(next_b);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:165:21
[INFO] [stdout]     |
[INFO] [stdout] 165 | /                     self.prev_a.insert(Segment {
[INFO] [stdout] 166 | |                         start: next_b.borrow_bound_after().unwrap(),
[INFO] [stdout] 167 | |                         end: next_a.end,
[INFO] [stdout] 168 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 165 |                     let _ = self.prev_a.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:220:21
[INFO] [stdout]     |
[INFO] [stdout] 220 | /                     self.prev_b.insert(Segment {
[INFO] [stdout] 221 | |                         start: next_a.borrow_bound_after().unwrap(),
[INFO] [stdout] 222 | |                         end: next_b.end,
[INFO] [stdout] 223 | |                     });
[INFO] [stdout]     | |______________________^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 220 |                     let _ = self.prev_b.insert(Segment {
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Option::<T>::insert` that must be used
[INFO] [stdout]    --> src/set/ops/symmetric_difference.rs:245:21
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     self.prev_a.insert(next_a);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to set a value, consider assignment instead
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 245 |                     let _ = self.prev_a.insert(next_a);
[INFO] [stdout]     |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 43.87s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.3.4
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "fba00561d168eef47d1500f9a1d020e0de1ab9cbb97ec52313d358c7b4d3e02f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fba00561d168eef47d1500f9a1d020e0de1ab9cbb97ec52313d358c7b4d3e02f", kill_on_drop: false }`
[INFO] [stdout] fba00561d168eef47d1500f9a1d020e0de1ab9cbb97ec52313d358c7b4d3e02f
