[INFO] fetching crate exoquant 0.2.0...
[INFO] testing exoquant-0.2.0 against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] extracting crate exoquant 0.2.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate exoquant 0.2.0 on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate exoquant 0.2.0
[INFO] finished tweaking crates.io crate exoquant 0.2.0
[INFO] tweaked toml for crates.io crate exoquant 0.2.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded lodepng v0.8.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dc65cf3f7b6249691a0ba6e68a276cefd1af1a8a1e80dae0bb7c50224baf9598
[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" "dc65cf3f7b6249691a0ba6e68a276cefd1af1a8a1e80dae0bb7c50224baf9598", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dc65cf3f7b6249691a0ba6e68a276cefd1af1a8a1e80dae0bb7c50224baf9598", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc65cf3f7b6249691a0ba6e68a276cefd1af1a8a1e80dae0bb7c50224baf9598", kill_on_drop: false }`
[INFO] [stdout] dc65cf3f7b6249691a0ba6e68a276cefd1af1a8a1e80dae0bb7c50224baf9598
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", 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] 3ed7c31ac5a8d2e2bee1b8a9770db9b16bcf571264ee55caa4cfbcdc5d9976c9
[INFO] running `Command { std: "docker" "start" "-a" "3ed7c31ac5a8d2e2bee1b8a9770db9b16bcf571264ee55caa4cfbcdc5d9976c9", kill_on_drop: false }`
[INFO] [stderr]    Compiling exoquant v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:53:48
[INFO] [stdout]    |
[INFO] [stdout] 53 |     pub fn to_color_counts(&self, colorspace: &ColorSpace) -> Vec<ColorCount> {
[INFO] [stdout]    |                                                ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:66:38
[INFO] [stdout]    |
[INFO] [stdout] 66 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = (&Color, &usize)> + 'a> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = (&Color, &usize)> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/quantizer.rs:211:39
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn optimize(self, optimizer: &Optimizer, num_iterations: usize) -> Quantizer {
[INFO] [stdout]     |                                       ^^^^^^^^^ help: use `dyn`: `dyn Optimizer`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:73:38
[INFO] [stdout]    |
[INFO] [stdout] 73 |                           image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:75:34
[INFO] [stdout]    |
[INFO] [stdout] 75 |                           -> Box<Iterator<Item = u8> + 'b> {
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = u8> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:87:44
[INFO] [stdout]    |
[INFO] [stdout] 87 | ...                   image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:89:40
[INFO] [stdout]    |
[INFO] [stdout] 89 | ...                   -> Box<Iterator<Item = usize> + 'b> {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/optimizer.rs:27:38
[INFO] [stdout]    |
[INFO] [stdout] 27 |                         colorspace: &ColorSpace,
[INFO] [stdout]    |                                      ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:13:29
[INFO] [stdout]    |
[INFO] [stdout] 13 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:16:34
[INFO] [stdout]    |
[INFO] [stdout] 16 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |                  -> Box<Iterator<Item = usize> + 'a>;
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:25:29
[INFO] [stdout]    |
[INFO] [stdout] 25 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:28:25
[INFO] [stdout]    |
[INFO] [stdout] 28 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:29:25
[INFO] [stdout]    |
[INFO] [stdout] 29 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:46:29
[INFO] [stdout]    |
[INFO] [stdout] 46 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:49:25
[INFO] [stdout]    |
[INFO] [stdout] 49 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:50:25
[INFO] [stdout]    |
[INFO] [stdout] 50 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:85:29
[INFO] [stdout]    |
[INFO] [stdout] 85 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:88:34
[INFO] [stdout]    |
[INFO] [stdout] 88 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:89:25
[INFO] [stdout]    |
[INFO] [stdout] 89 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.66s
[INFO] running `Command { std: "docker" "inspect" "3ed7c31ac5a8d2e2bee1b8a9770db9b16bcf571264ee55caa4cfbcdc5d9976c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3ed7c31ac5a8d2e2bee1b8a9770db9b16bcf571264ee55caa4cfbcdc5d9976c9", kill_on_drop: false }`
[INFO] [stdout] 3ed7c31ac5a8d2e2bee1b8a9770db9b16bcf571264ee55caa4cfbcdc5d9976c9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1c8ac9d2f1950aa16d5043279d904cac408f913547fc66446394294b28effea4
[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" "1c8ac9d2f1950aa16d5043279d904cac408f913547fc66446394294b28effea4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling bytemuck v1.7.2
[INFO] [stderr]    Compiling lodepng v0.8.1
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:53:48
[INFO] [stdout]    |
[INFO] [stdout] 53 |     pub fn to_color_counts(&self, colorspace: &ColorSpace) -> Vec<ColorCount> {
[INFO] [stdout]    |                                                ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:66:38
[INFO] [stdout]    |
[INFO] [stdout] 66 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = (&Color, &usize)> + 'a> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = (&Color, &usize)> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/quantizer.rs:211:39
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn optimize(self, optimizer: &Optimizer, num_iterations: usize) -> Quantizer {
[INFO] [stdout]     |                                       ^^^^^^^^^ help: use `dyn`: `dyn Optimizer`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:73:38
[INFO] [stdout]    |
[INFO] [stdout] 73 |                           image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:75:34
[INFO] [stdout]    |
[INFO] [stdout] 75 |                           -> Box<Iterator<Item = u8> + 'b> {
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = u8> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:87:44
[INFO] [stdout]    |
[INFO] [stdout] 87 | ...                   image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:89:40
[INFO] [stdout]    |
[INFO] [stdout] 89 | ...                   -> Box<Iterator<Item = usize> + 'b> {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/optimizer.rs:27:38
[INFO] [stdout]    |
[INFO] [stdout] 27 |                         colorspace: &ColorSpace,
[INFO] [stdout]    |                                      ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:13:29
[INFO] [stdout]    |
[INFO] [stdout] 13 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:16:34
[INFO] [stdout]    |
[INFO] [stdout] 16 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |                  -> Box<Iterator<Item = usize> + 'a>;
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:25:29
[INFO] [stdout]    |
[INFO] [stdout] 25 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:28:25
[INFO] [stdout]    |
[INFO] [stdout] 28 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:29:25
[INFO] [stdout]    |
[INFO] [stdout] 29 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:46:29
[INFO] [stdout]    |
[INFO] [stdout] 46 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:49:25
[INFO] [stdout]    |
[INFO] [stdout] 49 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:50:25
[INFO] [stdout]    |
[INFO] [stdout] 50 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:85:29
[INFO] [stdout]    |
[INFO] [stdout] 85 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:88:34
[INFO] [stdout]    |
[INFO] [stdout] 88 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:89:25
[INFO] [stdout]    |
[INFO] [stdout] 89 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rgb v0.8.29
[INFO] [stderr]    Compiling exoquant v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:53:48
[INFO] [stdout]    |
[INFO] [stdout] 53 |     pub fn to_color_counts(&self, colorspace: &ColorSpace) -> Vec<ColorCount> {
[INFO] [stdout]    |                                                ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/histogram.rs:66:38
[INFO] [stdout]    |
[INFO] [stdout] 66 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = (&Color, &usize)> + 'a> {
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = (&Color, &usize)> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/quantizer.rs:211:39
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn optimize(self, optimizer: &Optimizer, num_iterations: usize) -> Quantizer {
[INFO] [stdout]     |                                       ^^^^^^^^^ help: use `dyn`: `dyn Optimizer`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:73:38
[INFO] [stdout]    |
[INFO] [stdout] 73 |                           image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:75:34
[INFO] [stdout]    |
[INFO] [stdout] 75 |                           -> Box<Iterator<Item = u8> + 'b> {
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = u8> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:87:44
[INFO] [stdout]    |
[INFO] [stdout] 87 | ...                   image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/remapper.rs:89:40
[INFO] [stdout]    |
[INFO] [stdout] 89 | ...                   -> Box<Iterator<Item = usize> + 'b> {
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'b`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/optimizer.rs:27:38
[INFO] [stdout]    |
[INFO] [stdout] 27 |                         colorspace: &ColorSpace,
[INFO] [stdout]    |                                      ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:13:29
[INFO] [stdout]    |
[INFO] [stdout] 13 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:16:34
[INFO] [stdout]    |
[INFO] [stdout] 16 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:17:25
[INFO] [stdout]    |
[INFO] [stdout] 17 |                  -> Box<Iterator<Item = usize> + 'a>;
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:25:29
[INFO] [stdout]    |
[INFO] [stdout] 25 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:28:25
[INFO] [stdout]    |
[INFO] [stdout] 28 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:29:25
[INFO] [stdout]    |
[INFO] [stdout] 29 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:46:29
[INFO] [stdout]    |
[INFO] [stdout] 46 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:49:25
[INFO] [stdout]    |
[INFO] [stdout] 49 |                  _: &'a ColorSpace)
[INFO] [stdout]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:50:25
[INFO] [stdout]    |
[INFO] [stdout] 50 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:85:29
[INFO] [stdout]    |
[INFO] [stdout] 85 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:88:34
[INFO] [stdout]    |
[INFO] [stdout] 88 |                  colorspace: &'a ColorSpace)
[INFO] [stdout]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ditherer.rs:89:25
[INFO] [stdout]    |
[INFO] [stdout] 89 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stdout]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 20 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 10.77s
[INFO] running `Command { std: "docker" "inspect" "1c8ac9d2f1950aa16d5043279d904cac408f913547fc66446394294b28effea4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c8ac9d2f1950aa16d5043279d904cac408f913547fc66446394294b28effea4", kill_on_drop: false }`
[INFO] [stdout] 1c8ac9d2f1950aa16d5043279d904cac408f913547fc66446394294b28effea4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen", 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] 78bc49ab77015a4c706389bd6c6c7c40b0b5f3472fad12de0c3809b4b814ee2e
[INFO] running `Command { std: "docker" "start" "-a" "78bc49ab77015a4c706389bd6c6c7c40b0b5f3472fad12de0c3809b4b814ee2e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/histogram.rs:53:48
[INFO] [stderr]    |
[INFO] [stderr] 53 |     pub fn to_color_counts(&self, colorspace: &ColorSpace) -> Vec<ColorCount> {
[INFO] [stderr]    |                                                ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/histogram.rs:66:38
[INFO] [stderr]    |
[INFO] [stderr] 66 |     pub fn iter<'a>(&'a self) -> Box<Iterator<Item = (&Color, &usize)> + 'a> {
[INFO] [stderr]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = (&Color, &usize)> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/quantizer.rs:211:39
[INFO] [stderr]     |
[INFO] [stderr] 211 |     pub fn optimize(self, optimizer: &Optimizer, num_iterations: usize) -> Quantizer {
[INFO] [stderr]     |                                       ^^^^^^^^^ help: use `dyn`: `dyn Optimizer`
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/remapper.rs:73:38
[INFO] [stderr]    |
[INFO] [stderr] 73 |                           image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stderr]    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/remapper.rs:75:34
[INFO] [stderr]    |
[INFO] [stderr] 75 |                           -> Box<Iterator<Item = u8> + 'b> {
[INFO] [stderr]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = u8> + 'b`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/remapper.rs:87:44
[INFO] [stderr]    |
[INFO] [stderr] 87 | ...                   image: Box<Iterator<Item = Color> + 'b>,
[INFO] [stderr]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Color> + 'b`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/remapper.rs:89:40
[INFO] [stderr]    |
[INFO] [stderr] 89 | ...                   -> Box<Iterator<Item = usize> + 'b> {
[INFO] [stderr]    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'b`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/optimizer.rs:27:38
[INFO] [stderr]    |
[INFO] [stderr] 27 |                         colorspace: &ColorSpace,
[INFO] [stderr]    |                                      ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:13:29
[INFO] [stderr]    |
[INFO] [stderr] 13 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stderr]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:16:34
[INFO] [stderr]    |
[INFO] [stderr] 16 |                  colorspace: &'a ColorSpace)
[INFO] [stderr]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:17:25
[INFO] [stderr]    |
[INFO] [stderr] 17 |                  -> Box<Iterator<Item = usize> + 'a>;
[INFO] [stderr]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:25:29
[INFO] [stderr]    |
[INFO] [stderr] 25 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stderr]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:28:25
[INFO] [stderr]    |
[INFO] [stderr] 28 |                  _: &'a ColorSpace)
[INFO] [stderr]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:29:25
[INFO] [stderr]    |
[INFO] [stderr] 29 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stderr]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:46:29
[INFO] [stderr]    |
[INFO] [stderr] 46 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stderr]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:49:25
[INFO] [stderr]    |
[INFO] [stderr] 49 |                  _: &'a ColorSpace)
[INFO] [stderr]    |                         ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:50:25
[INFO] [stderr]    |
[INFO] [stderr] 50 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stderr]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:85:29
[INFO] [stderr]    |
[INFO] [stderr] 85 |                  image: Box<Iterator<Item = Colorf> + 'a>,
[INFO] [stderr]    |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = Colorf> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:88:34
[INFO] [stderr]    |
[INFO] [stderr] 88 |                  colorspace: &'a ColorSpace)
[INFO] [stderr]    |                                  ^^^^^^^^^^ help: use `dyn`: `dyn ColorSpace`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/ditherer.rs:89:25
[INFO] [stderr]    |
[INFO] [stderr] 89 |                  -> Box<Iterator<Item = usize> + 'a> {
[INFO] [stderr]    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn Iterator<Item = usize> + 'a`
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] 
[INFO] [stderr] warning: `exoquant` (lib) generated 20 warnings
[INFO] [stderr] warning: `exoquant` (lib test) generated 20 warnings (20 duplicates)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/exoquant-381e9940b7ac2432)
[INFO] [stdout] running 1 test
[INFO] [stderr]    Doc-tests exoquant
[INFO] [stdout] test histogram::tests::count_duplicates ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 12 tests
[INFO] [stdout] test src/histogram.rs - histogram::Histogram (line 24) ... ok
[INFO] [stdout] test src/histogram.rs - histogram::Histogram (line 17) ... ok
[INFO] [stdout] test src/quantizer.rs - quantizer::Quantizer (line 126) ... ok
[INFO] [stdout] test src/quantizer.rs - quantizer::Quantizer (line 114) ... ok
[INFO] [stdout] test src/remapper.rs - remapper::Remapper (line 12) ... ok
[INFO] [stdout] test src/remapper.rs - remapper::Remapper (line 22) ... ok
[INFO] [stdout] test src/basicapi.rs - basicapi::generate_palette (line 39) ... ok
[INFO] [stdout] test src/optimizer.rs - optimizer::Optimizer::optimize_palette (line 16) ... ok
[INFO] [stdout] test src/lib.rs - (line 13) ... ok
[INFO] [stdout] test src/basicapi.rs - basicapi::convert_to_indexed (line 8) ... ok
[INFO] [stdout] test src/quantizer.rs - quantizer::Quantizer::optimize (line 196) ... ok
[INFO] [stdout] test src/lib.rs - (line 32) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 12 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 15.05s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "78bc49ab77015a4c706389bd6c6c7c40b0b5f3472fad12de0c3809b4b814ee2e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "78bc49ab77015a4c706389bd6c6c7c40b0b5f3472fad12de0c3809b4b814ee2e", kill_on_drop: false }`
[INFO] [stdout] 78bc49ab77015a4c706389bd6c6c7c40b0b5f3472fad12de0c3809b4b814ee2e