[INFO] fetching crate resq-flamegraph 0.1.10... [INFO] testing resq-flamegraph-0.1.10 against master#562dee4820c458d823175268e41601d4c060588a for pr-154210-2 [INFO] extracting crate resq-flamegraph 0.1.10 into /workspace/builds/worker-2-tc1/source [INFO] started tweaking crates.io crate resq-flamegraph 0.1.10 [INFO] finished tweaking crates.io crate resq-flamegraph 0.1.10 [INFO] tweaked toml for crates.io crate resq-flamegraph 0.1.10 written to /workspace/builds/worker-2-tc1/source/Cargo.toml [INFO] validating manifest of crates.io crate resq-flamegraph 0.1.10 on toolchain 562dee4820c458d823175268e41601d4c060588a [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+562dee4820c458d823175268e41601d4c060588a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate crates.io crate resq-flamegraph 0.1.10 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" "+562dee4820c458d823175268e41601d4c060588a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Updating crates.io index [INFO] [stderr] Downloading crates ... [INFO] [stderr] Downloaded lru v0.16.3 [INFO] [stderr] Downloaded kasuari v0.4.12 [INFO] [stderr] Downloaded wasm-bindgen-shared v0.2.117 [INFO] [stderr] Downloaded unicode-truncate v2.0.1 [INFO] [stderr] Downloaded ratatui v0.30.0 [INFO] [stderr] Downloaded is-wsl v0.4.0 [INFO] [stderr] Downloaded is-docker v0.2.0 [INFO] [stderr] Downloaded castaway v0.2.4 [INFO] [stderr] Downloaded wasm-bindgen-futures v0.4.67 [INFO] [stderr] Downloaded signal-hook-mio v0.2.5 [INFO] [stderr] Downloaded pathdiff v0.2.3 [INFO] [stderr] Downloaded resq-tui v0.1.4 [INFO] [stderr] Downloaded ratatui-crossterm v0.1.0 [INFO] [stderr] Downloaded open v5.3.3 [INFO] [stderr] Downloaded ratatui-macros v0.7.0 [INFO] [stderr] Downloaded wasm-bindgen-macro v0.2.117 [INFO] [stderr] Downloaded line-clipping v0.3.7 [INFO] [stderr] Downloaded str_stack v0.1.0 [INFO] [stderr] Downloaded document-features v0.2.12 [INFO] [stderr] Downloaded instability v0.3.12 [INFO] [stderr] Downloaded litrs v1.0.0 [INFO] [stderr] Downloaded rgb v0.8.53 [INFO] [stderr] Downloaded wasm-bindgen-macro-support v0.2.117 [INFO] [stderr] Downloaded wasm-streams v0.5.0 [INFO] [stderr] Downloaded wasm-bindgen v0.2.117 [INFO] [stderr] Downloaded cmake v0.1.58 [INFO] [stderr] Downloaded compact_str v0.9.0 [INFO] [stderr] Downloaded js-sys v0.3.94 [INFO] [stderr] Downloaded inferno v0.12.6 [INFO] [stderr] Downloaded crossterm v0.29.0 [INFO] [stderr] Downloaded hyper v1.9.0 [INFO] [stderr] Downloaded iri-string v0.7.12 [INFO] [stderr] Downloaded reqwest v0.13.2 [INFO] [stderr] Downloaded quick-xml v0.39.2 [INFO] [stderr] Downloaded ratatui-core v0.1.0 [INFO] [stderr] Downloaded aws-lc-rs v1.16.2 [INFO] [stderr] Downloaded ratatui-widgets v0.3.0 [INFO] [stderr] Downloaded web-sys v0.3.94 [INFO] [stderr] Downloaded libc v0.2.184 [INFO] [stderr] Downloaded aws-lc-sys v0.39.1 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "+562dee4820c458d823175268e41601d4c060588a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] f0a3bca35ad7a809e0cd1950217021000dcdec90e755fefdbc13a850e5545fcd [INFO] running `Command { std: "docker" "start" "-a" "f0a3bca35ad7a809e0cd1950217021000dcdec90e755fefdbc13a850e5545fcd", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "f0a3bca35ad7a809e0cd1950217021000dcdec90e755fefdbc13a850e5545fcd", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "f0a3bca35ad7a809e0cd1950217021000dcdec90e755fefdbc13a850e5545fcd", kill_on_drop: false }` [INFO] [stdout] f0a3bca35ad7a809e0cd1950217021000dcdec90e755fefdbc13a850e5545fcd [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "+562dee4820c458d823175268e41601d4c060588a" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 3b232fcb2abeda5d63bf20f1fdbf6bed20b2a096883d06eb876385f82fbf6ec4 [INFO] running `Command { std: "docker" "start" "-a" "3b232fcb2abeda5d63bf20f1fdbf6bed20b2a096883d06eb876385f82fbf6ec4", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.184 [INFO] [stderr] Compiling itoa v1.0.18 [INFO] [stderr] Compiling foldhash v0.2.0 [INFO] [stderr] Compiling allocator-api2 v0.2.21 [INFO] [stderr] Compiling syn v2.0.117 [INFO] [stderr] Compiling strsim v0.11.1 [INFO] [stderr] Compiling dunce v1.0.5 [INFO] [stderr] Compiling fs_extra v1.3.0 [INFO] [stderr] Compiling unicode-segmentation v1.13.2 [INFO] [stderr] Compiling heck v0.5.0 [INFO] [stderr] Compiling bitflags v2.11.0 [INFO] [stderr] Compiling hashbrown v0.16.1 [INFO] [stderr] Compiling rustversion v1.0.22 [INFO] [stderr] Compiling futures-sink v0.3.32 [INFO] [stderr] Compiling aws-lc-rs v1.16.2 [INFO] [stderr] Compiling ident_case v1.0.1 [INFO] [stderr] Compiling http v1.4.0 [INFO] [stderr] Compiling either v1.15.0 [INFO] [stderr] Compiling litemap v0.8.2 [INFO] [stderr] Compiling signal-hook v0.3.18 [INFO] [stderr] Compiling icu_normalizer_data v2.2.0 [INFO] [stderr] Compiling unicode-width v0.2.2 [INFO] [stderr] Compiling itertools v0.14.0 [INFO] [stderr] Compiling icu_properties_data v2.2.0 [INFO] [stderr] Compiling instability v0.3.12 [INFO] [stderr] Compiling static_assertions v1.1.0 [INFO] [stderr] Compiling indoc v2.0.7 [INFO] [stderr] Compiling castaway v0.2.4 [INFO] [stderr] Compiling indexmap v2.13.0 [INFO] [stderr] Compiling compact_str v0.9.0 [INFO] [stderr] Compiling lru v0.16.3 [INFO] [stderr] Compiling http-body v1.0.1 [INFO] [stderr] Compiling convert_case v0.10.0 [INFO] [stderr] Compiling tracing-core v0.1.36 [INFO] [stderr] Compiling rustix v1.1.4 [INFO] [stderr] Compiling errno v0.3.14 [INFO] [stderr] Compiling parking_lot_core v0.9.12 [INFO] [stderr] Compiling mio v1.2.0 [INFO] [stderr] Compiling signal-hook-registry v1.4.8 [INFO] [stderr] Compiling parking_lot v0.12.5 [INFO] [stderr] Compiling jobserver v0.1.34 [INFO] [stderr] Compiling socket2 v0.6.3 [INFO] [stderr] Compiling powerfmt v0.2.0 [INFO] [stderr] Compiling cc v1.2.58 [INFO] [stderr] Compiling rustls v0.23.37 [INFO] [stderr] Compiling futures-task v0.3.32 [INFO] [stderr] Compiling futures-io v0.3.32 [INFO] [stderr] Compiling untrusted v0.9.0 [INFO] [stderr] Compiling deranged v0.5.8 [INFO] [stderr] Compiling futures-util v0.3.32 [INFO] [stderr] Compiling tracing v0.1.44 [INFO] [stderr] Compiling num_threads v0.1.7 [INFO] [stderr] Compiling unicode-truncate v2.0.1 [INFO] [stderr] Compiling utf8parse v0.2.2 [INFO] [stderr] Compiling subtle v2.6.1 [INFO] [stderr] Compiling num-conv v0.2.1 [INFO] [stderr] Compiling linux-raw-sys v0.12.1 [INFO] [stderr] Compiling time-core v0.1.8 [INFO] [stderr] Compiling litrs v1.0.0 [INFO] [stderr] Compiling anstyle-parse v1.0.0 [INFO] [stderr] Compiling signal-hook-mio v0.2.5 [INFO] [stderr] Compiling futures-channel v0.3.32 [INFO] [stderr] Compiling line-clipping v0.3.7 [INFO] [stderr] Compiling cmake v0.1.58 [INFO] [stderr] Compiling unicase v2.9.0 [INFO] [stderr] Compiling colorchoice v1.0.5 [INFO] [stderr] Compiling document-features v0.2.12 [INFO] [stderr] Compiling is_terminal_polyfill v1.70.2 [INFO] [stderr] Compiling anstyle-query v1.1.5 [INFO] [stderr] Compiling anstyle v1.0.14 [INFO] [stderr] Compiling ahash v0.8.12 [INFO] [stderr] Compiling time v0.3.47 [INFO] [stderr] Compiling mime_guess v2.0.5 [INFO] [stderr] Compiling anstream v1.0.0 [INFO] [stderr] Compiling aws-lc-sys v0.39.1 [INFO] [stderr] Compiling sync_wrapper v1.0.2 [INFO] [stderr] Compiling clap_lex v1.1.0 [INFO] [stderr] Compiling ipnet v2.12.0 [INFO] [stderr] Compiling openssl-probe v0.2.1 [INFO] [stderr] Compiling clap_builder v4.6.0 [INFO] [stderr] Compiling synstructure v0.13.2 [INFO] [stderr] Compiling darling_core v0.23.0 [INFO] [stderr] Compiling rustls-native-certs v0.8.3 [INFO] [stderr] Compiling serde_json v1.0.149 [INFO] [stderr] Compiling getrandom v0.3.4 [INFO] [stderr] Compiling form_urlencoded v1.2.2 [INFO] [stderr] Compiling is-docker v0.2.0 [INFO] [stderr] Compiling env_filter v1.0.1 [INFO] [stderr] Compiling arrayvec v0.7.6 [INFO] [stderr] Compiling bytemuck v1.25.0 [INFO] [stderr] Compiling iri-string v0.7.12 [INFO] [stderr] Compiling hashbrown v0.14.5 [INFO] [stderr] Compiling rgb v0.8.53 [INFO] [stderr] Compiling dashmap v6.1.0 [INFO] [stderr] Compiling zerofrom-derive v0.1.7 [INFO] [stderr] Compiling yoke-derive v0.8.2 [INFO] [stderr] Compiling zerovec-derive v0.11.3 [INFO] [stderr] Compiling displaydoc v0.2.5 [INFO] [stderr] Compiling tokio-macros v2.6.1 [INFO] [stderr] Compiling zerofrom v0.1.7 [INFO] [stderr] Compiling thiserror-impl v2.0.18 [INFO] [stderr] Compiling yoke v0.8.2 [INFO] [stderr] Compiling strum_macros v0.27.2 [INFO] [stderr] Compiling zerovec v0.11.6 [INFO] [stderr] Compiling zerotrie v0.2.4 [INFO] [stderr] Compiling tokio v1.50.0 [INFO] [stderr] Compiling darling_macro v0.23.0 [INFO] [stderr] Compiling tinystr v0.8.3 [INFO] [stderr] Compiling potential_utf v0.1.5 [INFO] [stderr] Compiling icu_locale_core v2.2.0 [INFO] [stderr] Compiling icu_collections v2.2.0 [INFO] [stderr] Compiling darling v0.23.0 [INFO] [stderr] Compiling thiserror v2.0.18 [INFO] [stderr] Compiling kasuari v0.4.12 [INFO] [stderr] Compiling derive_more-impl v2.1.1 [INFO] [stderr] Compiling serde_derive v1.0.228 [INFO] [stderr] Compiling icu_provider v2.2.0 [INFO] [stderr] Compiling icu_properties v2.2.0 [INFO] [stderr] Compiling derive_more v2.1.1 [INFO] [stderr] Compiling icu_normalizer v2.2.0 [INFO] [stderr] Compiling crossterm v0.29.0 [INFO] [stderr] Compiling clap_derive v4.6.0 [INFO] [stderr] Compiling strum v0.27.2 [INFO] [stderr] Compiling ratatui-core v0.1.0 [INFO] [stderr] Compiling num-format v0.4.4 [INFO] [stderr] Compiling idna_adapter v1.2.1 [INFO] [stderr] Compiling env_logger v0.11.10 [INFO] [stderr] Compiling idna v1.1.0 [INFO] [stderr] Compiling is-wsl v0.4.0 [INFO] [stderr] Compiling ratatui-widgets v0.3.0 [INFO] [stderr] Compiling ratatui-crossterm v0.1.0 [INFO] [stderr] Compiling url v2.5.8 [INFO] [stderr] Compiling clap v4.6.0 [INFO] [stderr] Compiling crossbeam-channel v0.5.15 [INFO] [stderr] Compiling http-body-util v0.1.3 [INFO] [stderr] Compiling ratatui-macros v0.7.0 [INFO] [stderr] Compiling quick-xml v0.39.2 [INFO] [stderr] Compiling ratatui v0.30.0 [INFO] [stderr] Compiling str_stack v0.1.0 [INFO] [stderr] Compiling pathdiff v0.2.3 [INFO] [stderr] Compiling open v5.3.3 [INFO] [stderr] Compiling glob v0.3.3 [INFO] [stderr] Compiling serde v1.0.228 [INFO] [stderr] Compiling tokio-util v0.7.18 [INFO] [stderr] Compiling tower v0.5.3 [INFO] [stderr] Compiling inferno v0.12.6 [INFO] [stderr] Compiling h2 v0.4.13 [INFO] [stderr] Compiling tower-http v0.6.8 [INFO] [stderr] Compiling resq-tui v0.1.4 [INFO] [stderr] Compiling chrono v0.4.44 [INFO] [stderr] Compiling hyper v1.9.0 [INFO] [stderr] Compiling hyper-util v0.1.20 [INFO] [stderr] Compiling rustls-webpki v0.103.10 [INFO] [stderr] Compiling tokio-rustls v0.26.4 [INFO] [stderr] Compiling rustls-platform-verifier v0.6.2 [INFO] [stderr] Compiling hyper-rustls v0.27.7 [INFO] [stderr] Compiling reqwest v0.13.2 [INFO] [stderr] Compiling resq-flamegraph v0.1.10 (/opt/rustwide/workdir) [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 2m 52s [INFO] running `Command { std: "docker" "inspect" "3b232fcb2abeda5d63bf20f1fdbf6bed20b2a096883d06eb876385f82fbf6ec4", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "3b232fcb2abeda5d63bf20f1fdbf6bed20b2a096883d06eb876385f82fbf6ec4", kill_on_drop: false }` [INFO] [stdout] 3b232fcb2abeda5d63bf20f1fdbf6bed20b2a096883d06eb876385f82fbf6ec4 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "+562dee4820c458d823175268e41601d4c060588a" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] eb8c3b4598970bab506077c7fad7a62a3138bb5a2f917950f785594749771462 [INFO] running `Command { std: "docker" "start" "-a" "eb8c3b4598970bab506077c7fad7a62a3138bb5a2f917950f785594749771462", kill_on_drop: false }` [INFO] [stderr] Compiling resq-flamegraph v0.1.10 (/opt/rustwide/workdir) [INFO] [stderr] Finished `test` profile [unoptimized + debuginfo] target(s) in 1.67s [INFO] running `Command { std: "docker" "inspect" "eb8c3b4598970bab506077c7fad7a62a3138bb5a2f917950f785594749771462", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "eb8c3b4598970bab506077c7fad7a62a3138bb5a2f917950f785594749771462", kill_on_drop: false }` [INFO] [stdout] eb8c3b4598970bab506077c7fad7a62a3138bb5a2f917950f785594749771462 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "+562dee4820c458d823175268e41601d4c060588a" "test" "--frozen", kill_on_drop: false }` [INFO] [stdout] 43e8f6a71c4aa400f1958c5f51fd35cb4efd62865df6268efc71d3a4939d1c0b [INFO] running `Command { std: "docker" "start" "-a" "43e8f6a71c4aa400f1958c5f51fd35cb4efd62865df6268efc71d3a4939d1c0b", kill_on_drop: false }` [INFO] [stderr] Finished `test` profile [unoptimized + debuginfo] target(s) in 0.32s [INFO] [stderr] Running unittests src/main.rs (/opt/rustwide/target/debug/deps/resq_flame-085ade9b5a388b25) [INFO] [stdout] [INFO] [stdout] running 11 tests [INFO] [stdout] test tests::app_error_display ... ok [INFO] [stdout] test tests::cpuprofile_to_folded_empty_samples ... ok [INFO] [stdout] test tests::cpuprofile_to_folded_anonymous_function ... ok [INFO] [stdout] test tests::parse_bpftrace_output_empty ... ok [INFO] [stdout] test tests::cpuprofile_to_folded_multiple_samples ... ok [INFO] [stdout] test tests::cpuprofile_to_folded_simple_stack ... ok [INFO] [stdout] test tests::parse_folded_stacks_empty_input ... ok [INFO] [stdout] test tests::parse_folded_stacks_invalid_count ... ok [INFO] [stdout] test tests::parse_bpftrace_output_no_stacks ... ok [INFO] [stdout] test tests::parse_bpftrace_output_valid ... ok [INFO] [stdout] test tests::parse_folded_stacks_valid ... ok [INFO] [stdout] [INFO] [stdout] test result: ok. 11 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s [INFO] [stdout] [INFO] running `Command { std: "docker" "inspect" "43e8f6a71c4aa400f1958c5f51fd35cb4efd62865df6268efc71d3a4939d1c0b", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "43e8f6a71c4aa400f1958c5f51fd35cb4efd62865df6268efc71d3a4939d1c0b", kill_on_drop: false }` [INFO] [stdout] 43e8f6a71c4aa400f1958c5f51fd35cb4efd62865df6268efc71d3a4939d1c0b