[INFO] fetching crate skiplist 0.3.0...
[INFO] checking skiplist-0.3.0 against master#cfbc6d4cf1acbac5c025acf8ed68929caa551df3 for pr-75494-beta
[INFO] extracting crate skiplist 0.3.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate skiplist 0.3.0 on toolchain cfbc6d4cf1acbac5c025acf8ed68929caa551df3
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate skiplist 0.3.0
[INFO] finished tweaking crates.io crate skiplist 0.3.0
[INFO] tweaked toml for crates.io crate skiplist 0.3.0 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 8dc5826c85153761d7b713f4acbf745b3b63892ba6e3391e57d04a714bcf7172
[INFO] running `Command { std: "docker" "start" "-a" "8dc5826c85153761d7b713f4acbf745b3b63892ba6e3391e57d04a714bcf7172", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8dc5826c85153761d7b713f4acbf745b3b63892ba6e3391e57d04a714bcf7172", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8dc5826c85153761d7b713f4acbf745b3b63892ba6e3391e57d04a714bcf7172", kill_on_drop: false }`
[INFO] [stdout] 8dc5826c85153761d7b713f4acbf745b3b63892ba6e3391e57d04a714bcf7172
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+cfbc6d4cf1acbac5c025acf8ed68929caa551df3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 408185f882c6d6f2843f7f0d47e5348e7c9d09cce0e25ff58415f5fc9fed22c8
[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" "408185f882c6d6f2843f7f0d47e5348e7c9d09cce0e25ff58415f5fc9fed22c8", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling rayon-core v1.7.1
[INFO] [stderr]     Checking either v1.6.0
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]     Checking itoa v0.4.6
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking ppv-lite86 v0.2.9
[INFO] [stderr]     Checking regex-syntax v0.6.18
[INFO] [stderr]     Checking same-file v1.0.6
[INFO] [stderr]     Checking half v1.6.0
[INFO] [stderr]     Checking oorandom v11.1.2
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling rayon v1.3.1
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking walkdir v2.3.1
[INFO] [stderr]     Checking itertools v0.9.0
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling cast v0.2.3
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]     Checking rand_pcg v0.2.1
[INFO] [stderr]     Checking crossbeam-queue v0.2.3
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking criterion-plot v0.4.3
[INFO] [stderr]     Checking regex v1.3.9
[INFO] [stderr]     Checking plotters v0.2.15
[INFO] [stderr]     Checking skiplist v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:249:17
[INFO] [stdout]     |
[INFO] [stdout] 249 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:254:9
[INFO] [stdout]     |
[INFO] [stdout] 254 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:882:21
[INFO] [stdout]     |
[INFO] [stdout] 882 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:961:21
[INFO] [stdout]     |
[INFO] [stdout] 961 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/ordered_skiplist.rs:1397:17
[INFO] [stdout]      |
[INFO] [stdout] 1397 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/skiplist.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:583:21
[INFO] [stdout]     |
[INFO] [stdout] 583 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:886:21
[INFO] [stdout]     |
[INFO] [stdout] 886 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/skiplist.rs:1120:17
[INFO] [stdout]      |
[INFO] [stdout] 1120 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skipmap.rs:309:17
[INFO] [stdout]     |
[INFO] [stdout] 309 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skipmap.rs:314:9
[INFO] [stdout]     |
[INFO] [stdout] 314 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/skipmap.rs:1293:17
[INFO] [stdout]      |
[INFO] [stdout] 1293 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 13 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking bstr v0.2.13
[INFO] [stderr]     Checking serde_cbor v0.11.1
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]     Checking csv v1.1.3
[INFO] [stderr]     Checking tinytemplate v1.1.0
[INFO] [stderr]     Checking criterion v0.3.3
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:249:17
[INFO] [stdout]     |
[INFO] [stdout] 249 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:254:9
[INFO] [stdout]     |
[INFO] [stdout] 254 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:882:21
[INFO] [stdout]     |
[INFO] [stdout] 882 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/ordered_skiplist.rs:961:21
[INFO] [stdout]     |
[INFO] [stdout] 961 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/ordered_skiplist.rs:1397:17
[INFO] [stdout]      |
[INFO] [stdout] 1397 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/skiplist.rs:95:17
[INFO] [stdout]    |
[INFO] [stdout] 95 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:100:9
[INFO] [stdout]     |
[INFO] [stdout] 100 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:583:21
[INFO] [stdout]     |
[INFO] [stdout] 583 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skiplist.rs:886:21
[INFO] [stdout]     |
[INFO] [stdout] 886 |                     mem::replace(&mut (*prev).next, mem::replace(&mut (*node).next, None));
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/skiplist.rs:1120:17
[INFO] [stdout]      |
[INFO] [stdout] 1120 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skipmap.rs:309:17
[INFO] [stdout]     |
[INFO] [stdout] 309 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/skipmap.rs:314:9
[INFO] [stdout]     |
[INFO] [stdout] 314 |         mem::replace(&mut self.head, new_head);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]     --> src/skipmap.rs:1293:17
[INFO] [stdout]      |
[INFO] [stdout] 1293 |                 mem::replace(&mut (*node).next, mem::replace(&mut next.next, None));
[INFO] [stdout]      |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout]      = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 13 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1m 01s
[INFO] running `Command { std: "docker" "inspect" "408185f882c6d6f2843f7f0d47e5348e7c9d09cce0e25ff58415f5fc9fed22c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "408185f882c6d6f2843f7f0d47e5348e7c9d09cce0e25ff58415f5fc9fed22c8", kill_on_drop: false }`
[INFO] [stdout] 408185f882c6d6f2843f7f0d47e5348e7c9d09cce0e25ff58415f5fc9fed22c8
