[INFO] cloning repository https://github.com/gfriloux/pgpilot [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/gfriloux/pgpilot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgfriloux%2Fpgpilot", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgfriloux%2Fpgpilot'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] da647611ffd259cbf57de5673a55a5cd9f31e89f [INFO] checking gfriloux/pgpilot against b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4 for pr-164582 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgfriloux%2Fpgpilot" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/gfriloux/pgpilot [INFO] finished tweaking git repo https://github.com/gfriloux/pgpilot [INFO] tweaked toml for git repo https://github.com/gfriloux/pgpilot written to /workspace/builds/worker-2-tc1/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/gfriloux/pgpilot on toolchain b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/gfriloux/pgpilot 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" "+b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Updating crates.io index [INFO] [stderr] Downloading crates ... [INFO] [stderr] Downloaded rustls-pki-types v1.15.0 [INFO] [stderr] Downloaded utf8-zero v0.8.1 [INFO] [stderr] Downloaded ureq v3.4.2 [INFO] [stderr] Downloaded ascii-canvas v4.0.0 [INFO] [stderr] Downloaded memsec v0.7.0 [INFO] [stderr] Downloaded xxhash-rust v0.8.17 [INFO] [stderr] Downloaded ena v0.14.4 [INFO] [stderr] Downloaded lalrpop-util v0.23.1 [INFO] [stderr] Downloaded bit-set v0.9.1 [INFO] [stderr] Downloaded swift-rs v1.0.8 [INFO] [stderr] Downloaded string_cache v0.9.0 [INFO] [stderr] Downloaded hybrid-array v0.4.13 [INFO] [stderr] Downloaded term v1.2.1 [INFO] [stderr] Downloaded phf_codegen v0.13.1 [INFO] [stderr] Downloaded time-macros v0.2.31 [INFO] [stderr] Downloaded generic-array v1.4.4 [INFO] [stderr] Downloaded uuid v1.26.1 [INFO] [stderr] Downloaded urlpattern v0.6.0 [INFO] [stderr] Downloaded buffered-reader v1.4.1 [INFO] [stderr] Downloaded tauri-plugin-dialog v2.8.0 [INFO] [stderr] Downloaded toml v1.1.3+spec-1.1.0 [INFO] [stderr] Downloaded json-patch v4.2.0 [INFO] [stderr] Downloaded infer v0.22.0 [INFO] [stderr] Downloaded servo_arc v0.4.3 [INFO] [stderr] Downloaded cssparser-macros v0.7.1 [INFO] [stderr] Downloaded string_cache_codegen v0.6.1 [INFO] [stderr] Downloaded ureq-proto v0.6.4 [INFO] [stderr] Downloaded cc v1.2.67 [INFO] [stderr] Downloaded tauri-plugin-fs v2.6.0 [INFO] [stderr] Downloaded tendril v0.5.1 [INFO] [stderr] Downloaded cssparser v0.37.0 [INFO] [stderr] Downloaded markup5ever v0.39.0 [INFO] [stderr] Downloaded web_atoms v0.2.5 [INFO] [stderr] Downloaded nettle-sys v2.3.2 [INFO] [stderr] Downloaded rumqttc v0.25.1 [INFO] [stderr] Downloaded cfb v0.14.0 [INFO] [stderr] Downloaded ctor v1.0.13 [INFO] [stderr] Downloaded camino v1.2.4 [INFO] [stderr] Downloaded tauri-plugin v2.7.0 [INFO] [stderr] Downloaded dom_query v0.28.0 [INFO] [stderr] Downloaded html5ever v0.39.0 [INFO] [stderr] Downloaded tauri-utils v2.10.0 [INFO] [stderr] Downloaded selectors v0.38.0 [INFO] [stderr] Downloaded objc2-exception-helper v0.1.1 [INFO] [stderr] Downloaded lalrpop v0.23.1 [INFO] [stderr] Downloaded time v0.3.53 [INFO] [stderr] Downloaded syn v3.0.6 [INFO] [stderr] Downloaded webview2-com v0.39.1 [INFO] [stderr] Downloaded tauri v2.12.0 [INFO] [stderr] Downloaded nettle v7.5.0 [INFO] [stderr] Downloaded sha1collisiondetection v0.3.4 [INFO] [stderr] Downloaded window-vibrancy v0.8.1 [INFO] [stderr] Downloaded sequoia-openpgp v2.4.1 [INFO] [stderr] Downloaded webview2-com-sys v0.39.1 [INFO] [stderr] Downloaded tray-icon v0.25.1 [INFO] [stderr] Downloaded muda v0.20.0 [INFO] [stderr] Downloaded keyboard-types v0.8.3 [INFO] [stderr] Downloaded dirs v7.0.0 [INFO] [stderr] Downloaded tauri-runtime-wry v2.12.0 [INFO] [stderr] Downloaded wry v0.57.0 [INFO] [stderr] Downloaded tao-macros v0.1.4 [INFO] [stderr] Downloaded objc2-user-notifications v0.3.2 [INFO] [stderr] Downloaded objc2-core-location v0.3.2 [INFO] [stderr] Downloaded tauri-runtime v2.12.0 [INFO] [stderr] Downloaded tao v0.37.1 [INFO] [stderr] Downloaded dlopen2 v0.8.2 [INFO] [stderr] Downloaded dlopen2_derive v0.4.3 [INFO] [stderr] Downloaded core-graphics v0.25.0 [INFO] [stderr] Downloaded tauri-macros v2.7.0 [INFO] [stderr] Downloaded tauri-codegen v2.7.0 [INFO] [stderr] Downloaded tauri-build v2.7.0 [INFO] [stderr] Downloaded tauri-winres v0.3.6 [INFO] [stderr] Downloaded embed-resource v3.0.11 [INFO] [stderr] Downloaded cargo_toml v1.0.1 [INFO] [stderr] Downloaded zvariant_derive v5.13.0 [INFO] [stderr] Downloaded zbus v5.17.0 [INFO] [stderr] Downloaded zvariant v5.13.0 [INFO] [stderr] Downloaded zbus_names v4.3.3 [INFO] [stderr] Downloaded zbus_macros v5.17.0 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:77db811e55d90add9212f6832c23229e3de5f1c1f9905e8cb07319ea15df73ac" "sleep" "infinity", kill_on_drop: false }` [INFO] [stdout] 5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6 [INFO] running `Command { std: "docker" "start" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6" "/opt/rustwide/cargo-home/bin/cargo" "+b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-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" "-w" "/opt/rustwide/workdir" "--user" "0:0" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6" "/opt/rustwide/cargo-home/bin/cargo" "+b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stderr] Compiling quote v1.0.46 [INFO] [stderr] Compiling proc-macro2 v1.0.106 [INFO] [stderr] Compiling libc v0.2.186 [INFO] [stderr] Compiling serde_core v1.0.229 [INFO] [stderr] Compiling pkg-config v0.3.33 [INFO] [stderr] Compiling target-lexicon v0.12.16 [INFO] [stderr] Compiling version-compare v0.2.1 [INFO] [stderr] Compiling serde v1.0.229 [INFO] [stderr] Compiling memchr v2.8.3 [INFO] [stderr] Compiling fastrand v2.4.1 [INFO] [stderr] Compiling siphasher v1.0.3 [INFO] [stderr] Checking smallvec v1.15.2 [INFO] [stderr] Checking pin-project-lite v0.2.17 [INFO] [stderr] Compiling thiserror v2.0.21 [INFO] [stderr] Compiling regex-syntax v0.8.11 [INFO] [stderr] Compiling new_debug_unreachable v1.0.6 [INFO] [stderr] Compiling scopeguard v1.2.0 [INFO] [stderr] Compiling precomputed-hash v0.1.1 [INFO] [stderr] Compiling lock_api v0.4.14 [INFO] [stderr] Compiling glob v0.3.3 [INFO] [stderr] Checking slab v0.4.12 [INFO] [stderr] Compiling stable_deref_trait v1.2.1 [INFO] [stderr] Compiling rustc-hash v2.1.3 [INFO] [stderr] Compiling phf_shared v0.13.1 [INFO] [stderr] Compiling winnow v1.0.4 [INFO] [stderr] Compiling anyhow v1.0.104 [INFO] [stderr] Compiling walkdir v2.5.0 [INFO] [stderr] Checking bytes v1.12.1 [INFO] [stderr] Checking percent-encoding v2.3.2 [INFO] [stderr] Compiling num-conv v0.2.2 [INFO] [stderr] Compiling phf_generator v0.13.1 [INFO] [stderr] Compiling time-core v0.1.9 [INFO] [stderr] Compiling typeid v1.0.3 [INFO] [stderr] Compiling phf_codegen v0.13.1 [INFO] [stderr] Compiling proc-macro-error-attr v1.0.4 [INFO] [stderr] Checking typenum v1.20.1 [INFO] [stderr] Compiling syn v1.0.109 [INFO] [stderr] Compiling itoa v1.0.18 [INFO] [stderr] Compiling aho-corasick v1.1.4 [INFO] [stderr] Compiling cfg-expr v0.15.8 [INFO] [stderr] Compiling proc-macro-error v1.0.4 [INFO] [stderr] Compiling erased-serde v0.4.10 [INFO] [stderr] Checking futures-channel v0.3.32 [INFO] [stderr] Compiling serde_json v1.0.151 [INFO] [stderr] Compiling zmij v1.0.23 [INFO] [stderr] Compiling either v1.16.0 [INFO] [stderr] Compiling syn v3.0.6 [INFO] [stderr] Compiling syn v2.0.119 [INFO] [stderr] Compiling string_cache_codegen v0.6.1 [INFO] [stderr] Checking getrandom v0.4.3 [INFO] [stderr] Checking errno v0.3.14 [INFO] [stderr] Compiling jobserver v0.1.35 [INFO] [stderr] Compiling parking_lot_core v0.9.12 [INFO] [stderr] Checking signal-hook-registry v1.4.8 [INFO] [stderr] Checking mio v1.2.2 [INFO] [stderr] Compiling cc v1.2.67 [INFO] [stderr] Compiling parking_lot v0.12.5 [INFO] [stderr] Checking socket2 v0.6.5 [INFO] [stderr] Compiling toml_writer v1.1.2+spec-1.1.0 [INFO] [stderr] Compiling rustix v1.1.4 [INFO] [stderr] Compiling toml_parser v1.1.2+spec-1.1.0 [INFO] [stderr] Compiling web_atoms v0.2.5 [INFO] [stderr] Compiling dtoa v1.0.11 [INFO] [stderr] Compiling string_cache v0.9.0 [INFO] [stderr] Checking rustls-pki-types v1.15.0 [INFO] [stderr] Checking http v1.4.2 [INFO] [stderr] Compiling dtoa-short v0.3.5 [INFO] [stderr] Compiling selectors v0.38.0 [INFO] [stderr] Compiling clang-sys v1.8.1 [INFO] [stderr] Compiling tendril v0.5.1 [INFO] [stderr] Compiling indexmap v1.9.3 [INFO] [stderr] Checking linux-raw-sys v0.12.1 [INFO] [stderr] Compiling alloc-no-stdlib v3.0.0 [INFO] [stderr] Compiling camino v1.2.4 [INFO] [stderr] Compiling alloc-stdlib v0.3.0 [INFO] [stderr] Compiling servo_arc v0.4.3 [INFO] [stderr] Compiling deranged v0.5.8 [INFO] [stderr] Compiling bit-vec v0.8.0 [INFO] [stderr] Compiling powerfmt v0.2.0 [INFO] [stderr] Checking regex-automata v0.4.16 [INFO] [stderr] Compiling aws-lc-rs v1.18.1 [INFO] [stderr] Compiling cmake v0.1.58 [INFO] [stderr] Compiling web-time v1.1.0 [INFO] [stderr] Compiling schemars v0.8.22 [INFO] [stderr] Compiling hashbrown v0.12.3 [INFO] [stderr] Compiling minimal-lexical v0.2.1 [INFO] [stderr] Checking option-ext v0.2.0 [INFO] [stderr] Checking dirs-sys v0.5.0 [INFO] [stderr] Compiling bit-set v0.8.0 [INFO] [stderr] Compiling nom v7.1.3 [INFO] [stderr] Compiling brotli-decompressor v6.0.1 [INFO] [stderr] Checking getrandom v0.2.17 [INFO] [stderr] Compiling quick-xml v0.41.0 [INFO] [stderr] Compiling libloading v0.8.9 [INFO] [stderr] Compiling foldhash v0.2.0 [INFO] [stderr] Compiling gio v0.18.4 [INFO] [stderr] Compiling dyn-clone v1.0.20 [INFO] [stderr] Compiling time v0.3.53 [INFO] [stderr] Compiling toml_datetime v1.1.1+spec-1.1.0 [INFO] [stderr] Compiling semver v1.0.28 [INFO] [stderr] Compiling aws-lc-sys v0.45.0 [INFO] [stderr] Compiling serde_spanned v1.1.1 [INFO] [stderr] Compiling rustc_version v0.4.1 [INFO] [stderr] Compiling toml v1.1.3+spec-1.1.0 [INFO] [stderr] Compiling ring v0.17.14 [INFO] [stderr] Compiling uuid v1.26.1 [INFO] [stderr] Checking bitflags v2.13.1 [INFO] [stderr] Compiling cfb v0.14.0 [INFO] [stderr] Compiling bindgen v0.72.1 [INFO] [stderr] Compiling brotli v9.0.0 [INFO] [stderr] Compiling serde-untagged v0.1.9 [INFO] [stderr] Compiling cexpr v0.6.0 [INFO] [stderr] Compiling infer v0.22.0 [INFO] [stderr] Checking generic-array v0.14.7 [INFO] [stderr] Checking regex v1.13.1 [INFO] [stderr] Compiling itertools v0.13.0 [INFO] [stderr] Compiling ctor v1.0.13 [INFO] [stderr] Compiling foldhash v0.1.5 [INFO] [stderr] Compiling lalrpop-util v0.23.1 [INFO] [stderr] Compiling crossbeam-utils v0.8.22 [INFO] [stderr] Compiling hashbrown v0.15.5 [INFO] [stderr] Compiling tempfile v3.27.0 [INFO] [stderr] Compiling term v1.2.1 [INFO] [stderr] Compiling fixedbitset v0.5.7 [INFO] [stderr] Compiling rustversion v1.0.23 [INFO] [stderr] Compiling bit-vec v0.9.1 [INFO] [stderr] Compiling keccak v0.1.6 [INFO] [stderr] Compiling rustls v0.23.45 [INFO] [stderr] Compiling petgraph v0.8.3 [INFO] [stderr] Compiling sha3 v0.10.9 [INFO] [stderr] Compiling ascii-canvas v4.0.0 [INFO] [stderr] Compiling bit-set v0.9.1 [INFO] [stderr] Checking block-buffer v0.10.4 [INFO] [stderr] Checking crypto-common v0.1.7 [INFO] [stderr] Checking hybrid-array v0.4.13 [INFO] [stderr] Compiling itertools v0.14.0 [INFO] [stderr] Checking form_urlencoded v1.2.2 [INFO] [stderr] Compiling ena v0.14.4 [INFO] [stderr] Compiling unicode-xid v0.2.6 [INFO] [stderr] error: could not compile `brotli` (lib) [INFO] [stderr] [INFO] [stderr] Caused by: [INFO] [stderr] process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4/bin/rustc --crate-name brotli --edition=2015 /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/brotli-9.0.0/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat,unused-externs-silent --crate-type lib --emit=dep-info,metadata,link -Z embed-metadata=no -C embed-bitcode=no --cfg 'feature="alloc-stdlib"' --cfg 'feature="std"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("alloc-stdlib", "benchmark", "billing", "default", "disable-timer", "disallow_large_window_size", "external-literal-probability", "ffi-api", "float64", "floating_point_context_mixing", "no-stdlib-ffi-binding", "pass-through-ffi-panics", "portable-float", "safe", "seccomp", "sha2", "simd", "std", "validation", "vector_scratch_space"))' -C metadata=633d643b221622bf -C extra-filename=-55ad0db416350880 --out-dir /opt/rustwide/target/debug/build/brotli/55ad0db416350880/out -L dependency=/opt/rustwide/target/debug/build/alloc-no-stdlib/15b7f7dfba36f7f9/out -L dependency=/opt/rustwide/target/debug/build/alloc-stdlib/e31db08ae1345912/out --extern alloc_no_stdlib=/opt/rustwide/target/debug/build/alloc-no-stdlib/15b7f7dfba36f7f9/out/liballoc_no_stdlib-15b7f7dfba36f7f9.rmeta --extern alloc_stdlib=/opt/rustwide/target/debug/build/alloc-stdlib/e31db08ae1345912/out/liballoc_stdlib-e31db08ae1345912.rmeta --extern brotli_decompressor=/opt/rustwide/target/debug/build/brotli-decompressor/05186eea6295b9ce/out/libbrotli_decompressor-05186eea6295b9ce.rmeta --cap-lints allow --cap-lints=forbid --force-warn=unused_crate_dependencies` (signal: 9, SIGKILL: kill) [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stderr] error: could not compile `syn` (lib) [INFO] [stderr] [INFO] [stderr] Caused by: [INFO] [stderr] process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/b26b4e75de6aac63fc6beeecebad5b3a5f84d2a4/bin/rustc --crate-name syn --edition=2021 /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/syn-3.0.6/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat,unused-externs-silent --crate-type lib --emit=dep-info,metadata,link -Z embed-metadata=no -C embed-bitcode=no --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="extra-traits"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="visit-mut"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("clone-impls", "default", "derive", "extra-traits", "fold", "full", "parsing", "printing", "proc-macro", "test", "visit", "visit-mut"))' -C metadata=820cfe82dbbc580c -C extra-filename=-85af4d5a9725e3f8 --out-dir /opt/rustwide/target/debug/build/syn/85af4d5a9725e3f8/out -L dependency=/opt/rustwide/target/debug/build/proc-macro2/a2d87d99a0278af7/out -L dependency=/opt/rustwide/target/debug/build/unicode-ident/8c98a1a0e58216a9/out --extern proc_macro2=/opt/rustwide/target/debug/build/proc-macro2/a2d87d99a0278af7/out/libproc_macro2-a2d87d99a0278af7.rmeta --extern quote=/opt/rustwide/target/debug/build/quote/834fbed87a66ebbb/out/libquote-834fbed87a66ebbb.rmeta --extern unicode_ident=/opt/rustwide/target/debug/build/unicode-ident/8c98a1a0e58216a9/out/libunicode_ident-8c98a1a0e58216a9.rmeta --cap-lints allow --cap-lints=forbid --force-warn=unused_crate_dependencies` (signal: 9, SIGKILL: kill) [INFO] running `Command { std: "docker" "inspect" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6", kill_on_drop: false }` [INFO] [stdout] 5bf0c8fe8be5b1bdd1f439e559fc38afbba3f4889ff4a6350c3cc390e30d0eb6