[INFO] fetching crate weighted_levenshtein 0.2.0...
[INFO] testing weighted_levenshtein-0.2.0 against try#33835004928d3bf65db4d4712e1330766263b0bd for pr-155739-1
[INFO] extracting crate weighted_levenshtein 0.2.0 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate weighted_levenshtein 0.2.0
[INFO] finished tweaking crates.io crate weighted_levenshtein 0.2.0
[INFO] tweaked toml for crates.io crate weighted_levenshtein 0.2.0 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate weighted_levenshtein 0.2.0 on toolchain 33835004928d3bf65db4d4712e1330766263b0bd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 1 package to latest compatible version
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4c9d9549f905e779f8bad88d58a667ca1e2123116003585d3150ebc88aeae585
[INFO] running `Command { std: "docker" "start" "-a" "4c9d9549f905e779f8bad88d58a667ca1e2123116003585d3150ebc88aeae585", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4c9d9549f905e779f8bad88d58a667ca1e2123116003585d3150ebc88aeae585", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4c9d9549f905e779f8bad88d58a667ca1e2123116003585d3150ebc88aeae585", kill_on_drop: false }`
[INFO] [stdout] 4c9d9549f905e779f8bad88d58a667ca1e2123116003585d3150ebc88aeae585
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] adb138d4c0ec055826e3c72cadc23e5f945f476862ad3518c374d7283b8fade1
[INFO] running `Command { std: "docker" "start" "-a" "adb138d4c0ec055826e3c72cadc23e5f945f476862ad3518c374d7283b8fade1", kill_on_drop: false }`
[INFO] [stderr]    Compiling weighted_levenshtein v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 32 |     default fn add_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:35:5
[INFO] [stdout]    |
[INFO] [stdout] 35 |     default fn rm_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     default fn sub_cost(&self, other: &Self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.15s
[INFO] running `Command { std: "docker" "inspect" "adb138d4c0ec055826e3c72cadc23e5f945f476862ad3518c374d7283b8fade1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "adb138d4c0ec055826e3c72cadc23e5f945f476862ad3518c374d7283b8fade1", kill_on_drop: false }`
[INFO] [stdout] adb138d4c0ec055826e3c72cadc23e5f945f476862ad3518c374d7283b8fade1
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 05658dac8a80581046bbf852927cf6fb1f7cf87f70eeea34b8575d2c965b70b9
[INFO] running `Command { std: "docker" "start" "-a" "05658dac8a80581046bbf852927cf6fb1f7cf87f70eeea34b8575d2c965b70b9", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-segmentation v1.13.2
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 32 |     default fn add_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:35:5
[INFO] [stdout]    |
[INFO] [stdout] 35 |     default fn rm_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     default fn sub_cost(&self, other: &Self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling weighted_levenshtein v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:32:5
[INFO] [stdout]    |
[INFO] [stdout] 32 |     default fn add_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:35:5
[INFO] [stdout]    |
[INFO] [stdout] 35 |     default fn rm_cost(&self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: specialization is experimental
[INFO] [stdout]   --> src/lib.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 38 |     default fn sub_cost(&self, other: &Self) -> usize {
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stdout]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stdout]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stdout]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 1.05s
[INFO] running `Command { std: "docker" "inspect" "05658dac8a80581046bbf852927cf6fb1f7cf87f70eeea34b8575d2c965b70b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "05658dac8a80581046bbf852927cf6fb1f7cf87f70eeea34b8575d2c965b70b9", kill_on_drop: false }`
[INFO] [stdout] 05658dac8a80581046bbf852927cf6fb1f7cf87f70eeea34b8575d2c965b70b9
[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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+33835004928d3bf65db4d4712e1330766263b0bd" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] d843f5c726bb85f6bc3d9fd9f8ca54054fc6c3350df26212dc8837351931908c
[INFO] running `Command { std: "docker" "start" "-a" "d843f5c726bb85f6bc3d9fd9f8ca54054fc6c3350df26212dc8837351931908c", kill_on_drop: false }`
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:32:5
[INFO] [stderr]    |
[INFO] [stderr] 32 |     default fn add_cost(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     default fn rm_cost(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 38 |     default fn sub_cost(&self, other: &Self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: `weighted_levenshtein` (lib) generated 3 warnings
[INFO] [stderr] warning: `weighted_levenshtein` (lib test) generated 3 warnings (3 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/weighted_levenshtein-9ec219f3fdcbeaf2)
[INFO] [stdout] 
[INFO] [stdout] running 14 tests
[INFO] [stdout] test tests::bug_insert_at_beginning_of_longest_sequence ... ok
[INFO] [stdout] test tests::insertions_should_increase_the_distance ... ok
[INFO] [stdout] test tests::deletions_should_increase_the_distance ... ok
[INFO] [stdout] test tests::shortcut_cases ... ok
[INFO] [stdout] test tests::should_work_on_enum_slices ... ok
[INFO] [stdout] test tests::should_work_on_sentences ... ok
[INFO] [stdout] test tests::substitutions_should_increase_the_distance ... ok
[INFO] [stdout] test tests::should_work_on_integer_slices ... ok
[INFO] [stdout] test tests::identical_strings_should_have_zero_distance ... ok
[INFO] [stdout] test tests::test_cheap_delete ... ok
[INFO] [stdout] test tests::test_complex ... ok
[INFO] [stdout] test tests::test_expensive_subst ... ok
[INFO] [stdout] test tests::test_grapheme_distance ... ok
[INFO] [stdout] test tests::test_money ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 14 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests weighted_levenshtein
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:32:5
[INFO] [stderr]    |
[INFO] [stderr] 32 |     default fn add_cost(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     default fn rm_cost(&self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: specialization is experimental
[INFO] [stderr]   --> src/lib.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 38 |     default fn sub_cost(&self, other: &Self) -> usize {
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]    = help: add `#![feature(specialization)]` to the crate attributes to enable
[INFO] [stderr]    = note: this compiler was built on 2026-04-24; consider upgrading it if it is out of date
[INFO] [stderr]    = warning: unstable syntax can change at any point in the future, causing a hard error!
[INFO] [stderr]    = note: for more information, see issue #154045 <https://github.com/rust-lang/rust/issues/154045>
[INFO] [stderr] 
[INFO] [stderr] warning: 3 warnings emitted
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stdout] running 4 tests
[INFO] [stdout] test src/lib.rs - distance (line 94) ... ok
[INFO] [stdout] test src/lib.rs - distance (line 121) ... ok
[INFO] [stdout] test src/lib.rs - distance (line 85) ... ok
[INFO] [stdout] test src/lib.rs - distance (line 108) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.45s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d843f5c726bb85f6bc3d9fd9f8ca54054fc6c3350df26212dc8837351931908c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d843f5c726bb85f6bc3d9fd9f8ca54054fc6c3350df26212dc8837351931908c", kill_on_drop: false }`
[INFO] [stdout] d843f5c726bb85f6bc3d9fd9f8ca54054fc6c3350df26212dc8837351931908c
