[INFO] cloning repository https://github.com/Elttob/polyhaven-rs [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Elttob/polyhaven-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElttob%2Fpolyhaven-rs", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElttob%2Fpolyhaven-rs'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 6ae75ff5facf12c85191d05ac262f990b2253ee0 [INFO] checking Elttob/polyhaven-rs against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElttob%2Fpolyhaven-rs" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/Elttob/polyhaven-rs [INFO] finished tweaking git repo https://github.com/Elttob/polyhaven-rs [INFO] tweaked toml for git repo https://github.com/Elttob/polyhaven-rs written to /workspace/builds/worker-6-tc2/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/Elttob/polyhaven-rs on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/Elttob/polyhaven-rs 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 88ae683c71e52f4aa173214246313c48d11d5699f1903f89ba3687997a6837ac [INFO] running `Command { std: "docker" "start" "-a" "88ae683c71e52f4aa173214246313c48d11d5699f1903f89ba3687997a6837ac", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "88ae683c71e52f4aa173214246313c48d11d5699f1903f89ba3687997a6837ac", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "88ae683c71e52f4aa173214246313c48d11d5699f1903f89ba3687997a6837ac", kill_on_drop: false }` [INFO] [stdout] 88ae683c71e52f4aa173214246313c48d11d5699f1903f89ba3687997a6837ac [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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 -Dunmustuse_in_always_ok" "-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] ef3fa8b63f17de87e9dc045ccbd123f1faf8517df48e51f70e0084dbc525dd3b [INFO] running `Command { std: "docker" "start" "-a" "ef3fa8b63f17de87e9dc045ccbd123f1faf8517df48e51f70e0084dbc525dd3b", kill_on_drop: false }` [INFO] [stderr] Compiling tokio v1.20.1 [INFO] [stderr] Compiling futures-task v0.3.23 [INFO] [stderr] Compiling futures-util v0.3.23 [INFO] [stderr] Checking tracing v0.1.36 [INFO] [stderr] Checking mio v0.8.4 [INFO] [stderr] Checking openssl-sys v0.9.75 [INFO] [stderr] Compiling futures-channel v0.3.23 [INFO] [stderr] Compiling serde_derive v1.0.144 [INFO] [stderr] Checking http-body v0.4.5 [INFO] [stderr] Compiling serde_json v1.0.85 [INFO] [stderr] Compiling anyhow v1.0.62 [INFO] [stderr] Checking num-integer v0.1.45 [INFO] [stderr] Checking chrono v0.4.22 [INFO] [stderr] Checking openssl v0.10.41 [INFO] [stderr] Checking serde v1.0.144 [INFO] [stderr] Checking tokio-util v0.7.3 [INFO] [stderr] Checking native-tls v0.2.10 [INFO] [stderr] Checking tokio-native-tls v0.3.0 [INFO] [stderr] Checking h2 v0.3.14 [INFO] [stderr] Checking serde_urlencoded v0.7.1 [INFO] [stderr] Checking hyper v0.14.20 [INFO] [stderr] Checking hyper-tls v0.5.0 [INFO] [stderr] Checking reqwest v0.11.11 [INFO] [stderr] Checking polyhaven v0.3.0 (/opt/rustwide/workdir) [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:38:53 [INFO] [stdout] | [INFO] [stdout] 38 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 39 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 40 | | "hdr" => Self::Hdr, [INFO] [stdout] 41 | | "exr" => Self::Exr, [INFO] [stdout] 42 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 43 | | }) [INFO] [stdout] 44 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] | [INFO] [stdout] = note: requested on the command line with `-D unmustuse-in-always-ok` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:39:9 [INFO] [stdout] | [INFO] [stdout] 39 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 40 | | "hdr" => Self::Hdr, [INFO] [stdout] 41 | | "exr" => Self::Exr, [INFO] [stdout] 42 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 43 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:58:53 [INFO] [stdout] | [INFO] [stdout] 58 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 59 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 60 | | "jpg_pretty" => Self::JpgPretty, [INFO] [stdout] 61 | | "jpg_plain" => Self::JpgPlain, [INFO] [stdout] ... | [INFO] [stdout] 64 | | }) [INFO] [stdout] 65 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:59:9 [INFO] [stdout] | [INFO] [stdout] 59 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 60 | | "jpg_pretty" => Self::JpgPretty, [INFO] [stdout] 61 | | "jpg_plain" => Self::JpgPlain, [INFO] [stdout] 62 | | "raw" => Self::Raw, [INFO] [stdout] 63 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 64 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:92:53 [INFO] [stdout] | [INFO] [stdout] 92 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 93 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 94 | | "ao" => Self::AO, [INFO] [stdout] 95 | | "arm" => Self::ARM, [INFO] [stdout] ... | [INFO] [stdout] 104 | | }) [INFO] [stdout] 105 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:93:9 [INFO] [stdout] | [INFO] [stdout] 93 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 94 | | "ao" => Self::AO, [INFO] [stdout] 95 | | "arm" => Self::ARM, [INFO] [stdout] 96 | | "bump" => Self::Bump, [INFO] [stdout] ... | [INFO] [stdout] 103 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 104 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:119:53 [INFO] [stdout] | [INFO] [stdout] 119 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 120 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 121 | | "exr" => Self::Exr, [INFO] [stdout] 122 | | "jpg" => Self::Jpg, [INFO] [stdout] ... | [INFO] [stdout] 125 | | }) [INFO] [stdout] 126 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:120:9 [INFO] [stdout] | [INFO] [stdout] 120 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 121 | | "exr" => Self::Exr, [INFO] [stdout] 122 | | "jpg" => Self::Jpg, [INFO] [stdout] 123 | | "png" => Self::Png, [INFO] [stdout] 124 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 125 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:112:37 [INFO] [stdout] | [INFO] [stdout] 112 | ... files::HDRIFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:126:29 [INFO] [stdout] | [INFO] [stdout] 126 | ... files::HDRIBackplateFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:197:45 [INFO] [stdout] | [INFO] [stdout] 197 | ... files::TextureFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:207:22 [INFO] [stdout] | [INFO] [stdout] 207 | (files::TextureMap::from_str(map_name).unwrap(), map) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:280:45 [INFO] [stdout] | [INFO] [stdout] 280 | ... files::TextureFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:290:22 [INFO] [stdout] | [INFO] [stdout] 290 | (files::TextureMap::from_str(map_name).unwrap(), map) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] error: could not compile `polyhaven` (lib test) due to 14 previous errors [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:38:53 [INFO] [stdout] | [INFO] [stdout] 38 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 39 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 40 | | "hdr" => Self::Hdr, [INFO] [stdout] 41 | | "exr" => Self::Exr, [INFO] [stdout] 42 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 43 | | }) [INFO] [stdout] 44 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] | [INFO] [stdout] = note: requested on the command line with `-D unmustuse-in-always-ok` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:39:9 [INFO] [stdout] | [INFO] [stdout] 39 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 40 | | "hdr" => Self::Hdr, [INFO] [stdout] 41 | | "exr" => Self::Exr, [INFO] [stdout] 42 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 43 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:58:53 [INFO] [stdout] | [INFO] [stdout] 58 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 59 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 60 | | "jpg_pretty" => Self::JpgPretty, [INFO] [stdout] 61 | | "jpg_plain" => Self::JpgPlain, [INFO] [stdout] ... | [INFO] [stdout] 64 | | }) [INFO] [stdout] 65 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:59:9 [INFO] [stdout] | [INFO] [stdout] 59 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 60 | | "jpg_pretty" => Self::JpgPretty, [INFO] [stdout] 61 | | "jpg_plain" => Self::JpgPlain, [INFO] [stdout] 62 | | "raw" => Self::Raw, [INFO] [stdout] 63 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 64 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:92:53 [INFO] [stdout] | [INFO] [stdout] 92 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 93 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 94 | | "ao" => Self::AO, [INFO] [stdout] 95 | | "arm" => Self::ARM, [INFO] [stdout] ... | [INFO] [stdout] 104 | | }) [INFO] [stdout] 105 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:93:9 [INFO] [stdout] | [INFO] [stdout] 93 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 94 | | "ao" => Self::AO, [INFO] [stdout] 95 | | "arm" => Self::ARM, [INFO] [stdout] 96 | | "bump" => Self::Bump, [INFO] [stdout] ... | [INFO] [stdout] 103 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 104 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:119:53 [INFO] [stdout] | [INFO] [stdout] 119 | fn from_str(s: &str) -> Result { [INFO] [stdout] | _____________________________________________________^ [INFO] [stdout] 120 | | Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 121 | | "exr" => Self::Exr, [INFO] [stdout] 122 | | "jpg" => Self::Jpg, [INFO] [stdout] ... | [INFO] [stdout] 125 | | }) [INFO] [stdout] 126 | | } [INFO] [stdout] | |_____^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/data/files.rs:120:9 [INFO] [stdout] | [INFO] [stdout] 120 | / Ok(match s.to_lowercase().as_str() { [INFO] [stdout] 121 | | "exr" => Self::Exr, [INFO] [stdout] 122 | | "jpg" => Self::Jpg, [INFO] [stdout] 123 | | "png" => Self::Png, [INFO] [stdout] 124 | | _ => Self::Unparsed(s.to_string()) [INFO] [stdout] 125 | | }) [INFO] [stdout] | |__________^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:112:37 [INFO] [stdout] | [INFO] [stdout] 112 | ... files::HDRIFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:126:29 [INFO] [stdout] | [INFO] [stdout] 126 | ... files::HDRIBackplateFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:197:45 [INFO] [stdout] | [INFO] [stdout] 197 | ... files::TextureFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:207:22 [INFO] [stdout] | [INFO] [stdout] 207 | (files::TextureMap::from_str(map_name).unwrap(), map) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:280:45 [INFO] [stdout] | [INFO] [stdout] 280 | ... files::TextureFormat::from_str(&format_str).unwrap(), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: this type will no longer be must used: Result [INFO] [stdout] --> src/json/files.rs:290:22 [INFO] [stdout] | [INFO] [stdout] 290 | (files::TextureMap::from_str(map_name).unwrap(), map) [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] error: could not compile `polyhaven` (lib) due to 14 previous errors [INFO] running `Command { std: "docker" "inspect" "ef3fa8b63f17de87e9dc045ccbd123f1faf8517df48e51f70e0084dbc525dd3b", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "ef3fa8b63f17de87e9dc045ccbd123f1faf8517df48e51f70e0084dbc525dd3b", kill_on_drop: false }` [INFO] [stdout] ef3fa8b63f17de87e9dc045ccbd123f1faf8517df48e51f70e0084dbc525dd3b