[INFO] cloning repository https://github.com/burdockcascade/rgfx [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/burdockcascade/rgfx" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fburdockcascade%2Frgfx", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fburdockcascade%2Frgfx'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 649ffff7682ada3c7696bd959287a74bfb3d7c6f [INFO] checking burdockcascade/rgfx against try#3248bace201b6227b0ff78eacc8b00d805551a86 for pr-153513 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fburdockcascade%2Frgfx" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/burdockcascade/rgfx [INFO] finished tweaking git repo https://github.com/burdockcascade/rgfx [INFO] tweaked toml for git repo https://github.com/burdockcascade/rgfx written to /workspace/builds/worker-4-tc2/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/burdockcascade/rgfx on toolchain 3248bace201b6227b0ff78eacc8b00d805551a86 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3248bace201b6227b0ff78eacc8b00d805551a86" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/burdockcascade/rgfx already has a lockfile, it will not be regenerated [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3248bace201b6227b0ff78eacc8b00d805551a86" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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" "+3248bace201b6227b0ff78eacc8b00d805551a86" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 94639c61b9d3f18a49742e4f7e16223bd6fed433e7c835da5f3c366abd8400af [INFO] running `Command { std: "docker" "start" "-a" "94639c61b9d3f18a49742e4f7e16223bd6fed433e7c835da5f3c366abd8400af", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "94639c61b9d3f18a49742e4f7e16223bd6fed433e7c835da5f3c366abd8400af", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "94639c61b9d3f18a49742e4f7e16223bd6fed433e7c835da5f3c366abd8400af", kill_on_drop: false }` [INFO] [stdout] 94639c61b9d3f18a49742e4f7e16223bd6fed433e7c835da5f3c366abd8400af [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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" "+3248bace201b6227b0ff78eacc8b00d805551a86" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] ee27a788152edd8e8593e56dc53677233eccc2a819d3746b613bbb57195288bb [INFO] running `Command { std: "docker" "start" "-a" "ee27a788152edd8e8593e56dc53677233eccc2a819d3746b613bbb57195288bb", kill_on_drop: false }` [INFO] [stderr] Checking cfg-if v1.0.4 [INFO] [stderr] Compiling quote v1.0.44 [INFO] [stderr] Checking bitflags v2.11.0 [INFO] [stderr] Checking log v0.4.29 [INFO] [stderr] Compiling rustix v1.1.4 [INFO] [stderr] Checking linux-raw-sys v0.12.1 [INFO] [stderr] Compiling libm v0.2.16 [INFO] [stderr] Compiling num-traits v0.2.19 [INFO] [stderr] Compiling wayland-sys v0.31.8 [INFO] [stderr] Compiling memchr v2.8.0 [INFO] [stderr] Compiling zerocopy v0.8.40 [INFO] [stderr] Compiling wayland-backend v0.3.12 [INFO] [stderr] Compiling wayland-client v0.31.12 [INFO] [stderr] Checking foldhash v0.2.0 [INFO] [stderr] Checking allocator-api2 v0.2.21 [INFO] [stderr] Checking arrayvec v0.7.6 [INFO] [stderr] Compiling thiserror v2.0.18 [INFO] [stderr] Checking libloading v0.8.9 [INFO] [stderr] Checking dlib v0.5.3 [INFO] [stderr] Compiling parking_lot_core v0.9.12 [INFO] [stderr] Compiling naga v28.0.0 [INFO] [stderr] Checking unicode-width v0.2.2 [INFO] [stderr] Checking rustix v0.38.44 [INFO] [stderr] Checking hashbrown v0.16.1 [INFO] [stderr] Checking lock_api v0.4.14 [INFO] [stderr] Checking hashbrown v0.15.5 [INFO] [stderr] Compiling syn v2.0.117 [INFO] [stderr] Checking codespan-reporting v0.12.0 [INFO] [stderr] Checking spirv v0.3.0+sdk-1.3.268.0 [INFO] [stderr] Checking gpu-descriptor-types v0.2.0 [INFO] [stderr] Checking ash v0.38.0+1.3.281 [INFO] [stderr] Compiling wgpu-hal v28.0.0 [INFO] [stderr] Checking presser v0.3.1 [INFO] [stderr] Checking slab v0.4.12 [INFO] [stderr] Checking unicode-ident v1.0.24 [INFO] [stderr] Checking khronos-egl v6.0.0 [INFO] [stderr] Compiling getrandom v0.3.4 [INFO] [stderr] Checking profiling v1.0.17 [INFO] [stderr] Checking memmap2 v0.9.10 [INFO] [stderr] Checking indexmap v2.13.0 [INFO] [stderr] Checking parking_lot v0.12.5 [INFO] [stderr] Compiling wgpu-core v28.0.0 [INFO] [stderr] Compiling getrandom v0.4.1 [INFO] [stderr] Compiling litrs v1.0.0 [INFO] [stderr] Checking gpu-descriptor v0.3.2 [INFO] [stderr] Compiling quick-xml v0.38.4 [INFO] [stderr] Checking rand_core v0.10.0 [INFO] [stderr] Checking ab_glyph v0.2.32 [INFO] [stderr] Compiling wgpu v28.0.0 [INFO] [stderr] Compiling winit v0.30.12 [INFO] [stderr] Checking tracing-core v0.1.36 [INFO] [stderr] Checking zune-core v0.5.1 [INFO] [stderr] Checking cpufeatures v0.3.0 [INFO] [stderr] Compiling cgmath v0.18.0 [INFO] [stderr] Checking zune-jpeg v0.5.12 [INFO] [stderr] Checking chacha20 v0.10.0 [INFO] [stderr] Checking x11-dl v2.21.0 [INFO] [stderr] Compiling document-features v0.2.12 [INFO] [stderr] Checking xkbcommon-dl v0.4.2 [INFO] [stderr] Checking smol_str v0.2.2 [INFO] [stderr] Checking dpi v0.1.2 [INFO] [stderr] Checking static_assertions v1.1.0 [INFO] [stderr] Checking tracing v0.1.44 [INFO] [stderr] Checking rand v0.10.0 [INFO] [stderr] Checking pollster v0.4.0 [INFO] [stderr] Compiling wayland-scanner v0.31.8 [INFO] [stderr] Checking ordered-float v5.1.0 [INFO] [stderr] Checking pxfm v0.1.27 [INFO] [stderr] Checking approx v0.4.0 [INFO] [stderr] Compiling bytemuck_derive v1.10.2 [INFO] [stderr] Compiling zerocopy-derive v0.8.40 [INFO] [stderr] Compiling thiserror-impl v2.0.18 [INFO] [stderr] Compiling thiserror-impl v1.0.69 [INFO] [stderr] Checking bytemuck v1.25.0 [INFO] [stderr] Checking thiserror v1.0.69 [INFO] [stderr] Checking wgpu-types v28.0.0 [INFO] [stderr] Checking tiny-skia-path v0.11.4 [INFO] [stderr] Checking tiny-skia v0.11.4 [INFO] [stderr] Checking moxcms v0.7.11 [INFO] [stderr] Checking polling v3.11.0 [INFO] [stderr] Checking gethostname v1.1.0 [INFO] [stderr] Checking x11rb v0.13.2 [INFO] [stderr] Checking calloop v0.13.0 [INFO] [stderr] Checking wayland-csd-frame v0.3.0 [INFO] [stderr] Checking wayland-protocols v0.32.10 [INFO] [stderr] Checking wayland-cursor v0.31.12 [INFO] [stderr] Checking calloop-wayland-source v0.3.0 [INFO] [stderr] Checking image v0.25.9 [INFO] [stderr] Checking half v2.7.1 [INFO] [stderr] Checking ahash v0.8.12 [INFO] [stderr] Checking gpu-allocator v0.28.0 [INFO] [stderr] Checking wayland-protocols-wlr v0.3.10 [INFO] [stderr] Checking wayland-protocols-plasma v0.3.10 [INFO] [stderr] Checking smithay-client-toolkit v0.19.2 [INFO] [stderr] Checking sctk-adwaita v0.10.1 [INFO] [stderr] Checking wgpu-core-deps-windows-linux-android v28.0.0 [INFO] [stderr] Checking rgfx v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused import: `AdapterInfo` [INFO] [stdout] --> src/renderer/state.rs:15:21 [INFO] [stdout] | [INFO] [stdout] 15 | use wgpu::{Adapter, AdapterInfo, BindGroup, BindGroupLayout, Buffer, Device, Instance, PresentMode, Queue, Surface}; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused import: `AdapterInfo` [INFO] [stdout] --> src/renderer/state.rs:15:21 [INFO] [stdout] | [INFO] [stdout] 15 | use wgpu::{Adapter, AdapterInfo, BindGroup, BindGroupLayout, Buffer, Device, Instance, PresentMode, Queue, Surface}; [INFO] [stdout] | ^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `scale` [INFO] [stdout] --> src/graphics/camera.rs:90:57 [INFO] [stdout] | [INFO] [stdout] 90 | Projection::Perspective { fov_y, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `scale: _` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `left` [INFO] [stdout] --> src/graphics/camera.rs:93:40 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^ help: try ignoring the field: `left: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `right` [INFO] [stdout] --> src/graphics/camera.rs:93:46 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `right: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `bottom` [INFO] [stdout] --> src/graphics/camera.rs:93:53 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^^ help: try ignoring the field: `bottom: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `top` [INFO] [stdout] --> src/graphics/camera.rs:93:61 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^ help: try ignoring the field: `top: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `scale` [INFO] [stdout] --> src/graphics/camera.rs:93:77 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `scale: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `scale` [INFO] [stdout] --> src/graphics/camera.rs:90:57 [INFO] [stdout] | [INFO] [stdout] 90 | Projection::Perspective { fov_y, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `scale: _` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `left` [INFO] [stdout] --> src/graphics/camera.rs:93:40 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^ help: try ignoring the field: `left: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `right` [INFO] [stdout] --> src/graphics/camera.rs:93:46 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `right: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `bottom` [INFO] [stdout] --> src/graphics/camera.rs:93:53 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^^ help: try ignoring the field: `bottom: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `top` [INFO] [stdout] --> src/graphics/camera.rs:93:61 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^ help: try ignoring the field: `top: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `scale` [INFO] [stdout] --> src/graphics/camera.rs:93:77 [INFO] [stdout] | [INFO] [stdout] 93 | Projection::Orthographic { left, right, bottom, top, near, far, scale, aspect } => { [INFO] [stdout] | ^^^^^ help: try ignoring the field: `scale: _` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `with_label` and `with_primitive_topology` are never used [INFO] [stdout] --> src/renderer/pipeline.rs:23:12 [INFO] [stdout] | [INFO] [stdout] 11 | impl<'a> PipelineBuilder<'a> { [INFO] [stdout] | ---------------------------- methods in this implementation [INFO] [stdout] ... [INFO] [stdout] 23 | pub fn with_label(mut self, label: &'a str) -> Self { [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 43 | pub fn with_primitive_topology(mut self, topology: PrimitiveTopology) -> Self { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: associated items `ATTRIBUTES` and `desc` are never used [INFO] [stdout] --> src/renderer/vertex.rs:38:11 [INFO] [stdout] | [INFO] [stdout] 37 | impl Vertex3D { [INFO] [stdout] | ------------- associated items in this implementation [INFO] [stdout] 38 | const ATTRIBUTES: [wgpu::VertexAttribute; 3] = vertex_attr_array![ [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 44 | pub fn desc() -> wgpu::VertexBufferLayout<'static> { [INFO] [stdout] | ^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `adapter` is never read [INFO] [stdout] --> src/renderer/state.rs:34:5 [INFO] [stdout] | [INFO] [stdout] 32 | pub struct RenderState { [INFO] [stdout] | ----------- field in this struct [INFO] [stdout] 33 | surface: Surface<'static>, [INFO] [stdout] 34 | adapter: Adapter, [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `RenderState` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `with_label` and `with_primitive_topology` are never used [INFO] [stdout] --> src/renderer/pipeline.rs:23:12 [INFO] [stdout] | [INFO] [stdout] 11 | impl<'a> PipelineBuilder<'a> { [INFO] [stdout] | ---------------------------- methods in this implementation [INFO] [stdout] ... [INFO] [stdout] 23 | pub fn with_label(mut self, label: &'a str) -> Self { [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 43 | pub fn with_primitive_topology(mut self, topology: PrimitiveTopology) -> Self { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: associated items `ATTRIBUTES` and `desc` are never used [INFO] [stdout] --> src/renderer/vertex.rs:38:11 [INFO] [stdout] | [INFO] [stdout] 37 | impl Vertex3D { [INFO] [stdout] | ------------- associated items in this implementation [INFO] [stdout] 38 | const ATTRIBUTES: [wgpu::VertexAttribute; 3] = vertex_attr_array![ [INFO] [stdout] | ^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 44 | pub fn desc() -> wgpu::VertexBufferLayout<'static> { [INFO] [stdout] | ^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `adapter` is never read [INFO] [stdout] --> src/renderer/state.rs:34:5 [INFO] [stdout] | [INFO] [stdout] 32 | pub struct RenderState { [INFO] [stdout] | ----------- field in this struct [INFO] [stdout] 33 | surface: Surface<'static>, [INFO] [stdout] 34 | adapter: Adapter, [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `RenderState` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `key` [INFO] [stdout] --> examples/hello_shapes.rs:50:35 [INFO] [stdout] | [INFO] [stdout] 50 | AppEvent::KeyReleased(key) => { [INFO] [stdout] | ^^^ help: if this is intentional, prefix it with an underscore: `_key` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `button` [INFO] [stdout] --> examples/hello_shapes.rs:57:42 [INFO] [stdout] | [INFO] [stdout] 57 | AppEvent::MouseButtonPressed(button) => { [INFO] [stdout] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_button` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `button` [INFO] [stdout] --> examples/hello_shapes.rs:60:43 [INFO] [stdout] | [INFO] [stdout] 60 | AppEvent::MouseButtonReleased(button) => { [INFO] [stdout] | ^^^^^^ help: if this is intentional, prefix it with an underscore: `_button` [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 42.49s [INFO] running `Command { std: "docker" "inspect" "ee27a788152edd8e8593e56dc53677233eccc2a819d3746b613bbb57195288bb", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "ee27a788152edd8e8593e56dc53677233eccc2a819d3746b613bbb57195288bb", kill_on_drop: false }` [INFO] [stdout] ee27a788152edd8e8593e56dc53677233eccc2a819d3746b613bbb57195288bb