[INFO] fetching crate nautilus-network 0.54.0...
[INFO] testing nautilus-network-0.54.0 against master#562dee4820c458d823175268e41601d4c060588a for pr-154210
[INFO] extracting crate nautilus-network 0.54.0 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate nautilus-network 0.54.0
[INFO] removed 0 missing tests
[INFO] finished tweaking crates.io crate nautilus-network 0.54.0
[INFO] tweaked toml for crates.io crate nautilus-network 0.54.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate nautilus-network 0.54.0 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 nautilus-network 0.54.0 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 target-lexicon v0.13.5
[INFO] [stderr]   Downloaded pyo3-build-config v0.28.2
[INFO] [stderr]   Downloaded rustpython-parser-vendored v0.4.0
[INFO] [stderr]   Downloaded unicode_names2_generator v1.3.0
[INFO] [stderr]   Downloaded implied-vol v2.0.0
[INFO] [stderr]   Downloaded rustpython-parser v0.4.0
[INFO] [stderr]   Downloaded evalexpr v11.3.1
[INFO] [stderr]   Downloaded unic-emoji-char v0.9.0
[INFO] [stderr]   Downloaded numpy v0.28.0
[INFO] [stderr]   Downloaded objc2-io-kit v0.3.1
[INFO] [stderr]   Downloaded pyo3-macros v0.28.2
[INFO] [stderr]   Downloaded pyo3-ffi v0.28.2
[INFO] [stderr]   Downloaded sysinfo v0.38.3
[INFO] [stderr]   Downloaded nautilus-cryptography v0.54.0
[INFO] [stderr]   Downloaded nautilus-model v0.54.0
[INFO] [stderr]   Downloaded unic-ucd-ident v0.9.0
[INFO] [stderr]   Downloaded pyo3-macros-backend v0.28.2
[INFO] [stderr]   Downloaded ustr v1.1.0
[INFO] [stderr]   Downloaded rustpython-ast v0.4.0
[INFO] [stderr]   Downloaded pyo3-async-runtimes v0.28.0
[INFO] [stderr]   Downloaded pyo3-stub-gen-derive v0.19.0
[INFO] [stderr]   Downloaded ntapi v0.4.3
[INFO] [stderr]   Downloaded pyo3 v0.28.2
[INFO] [stderr]   Downloaded pyo3-stub-gen v0.19.0
[INFO] [stderr]   Downloaded nautilus-indicators v0.54.0
[INFO] [stderr]   Downloaded nautilus-core v0.54.0
[INFO] [stderr]   Downloaded turmoil v0.7.1
[INFO] [stderr]   Downloaded rustpython-parser-core v0.4.0
[INFO] [stderr]   Downloaded pyo3-async-runtimes-macros v0.28.0
[INFO] [stderr]   Downloaded nautilus-common v0.54.0
[INFO] [stderr]   Downloaded unicode_names2 v1.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] f441654eefb17e70170de276e7cdd3dd22613425b5fb2b24b515b07954d763ab
[INFO] running `Command { std: "docker" "start" "-a" "f441654eefb17e70170de276e7cdd3dd22613425b5fb2b24b515b07954d763ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f441654eefb17e70170de276e7cdd3dd22613425b5fb2b24b515b07954d763ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f441654eefb17e70170de276e7cdd3dd22613425b5fb2b24b515b07954d763ab", kill_on_drop: false }`
[INFO] [stdout] f441654eefb17e70170de276e7cdd3dd22613425b5fb2b24b515b07954d763ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] cfbf5fcfd3189e5cfc2c9cf2a2834531e14c9f5cb2a976376dfd1bea83323e97
[INFO] running `Command { std: "docker" "start" "-a" "cfbf5fcfd3189e5cfc2c9cf2a2834531e14c9f5cb2a976376dfd1bea83323e97", kill_on_drop: false }`
[INFO] [stderr]    Compiling dunce v1.0.5
[INFO] [stderr]    Compiling fs_extra v1.3.0
[INFO] [stderr]    Compiling generic-array v0.14.9
[INFO] [stderr]    Compiling aws-lc-rs v1.16.0
[INFO] [stderr]    Compiling zerocopy v0.8.40
[INFO] [stderr]    Compiling value-bag v1.12.0
[INFO] [stderr]    Compiling rustls v0.23.37
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling jobserver v0.1.34
[INFO] [stderr]    Compiling getrandom v0.3.4
[INFO] [stderr]    Compiling serde_core v1.0.228
[INFO] [stderr]    Compiling slab v0.4.12
[INFO] [stderr]    Compiling winnow v0.7.14
[INFO] [stderr]    Compiling getrandom v0.4.1
[INFO] [stderr]    Compiling rand_core v0.10.0
[INFO] [stderr]    Compiling rust_decimal v1.40.0
[INFO] [stderr]    Compiling tracing v0.1.44
[INFO] [stderr]    Compiling log v0.4.29
[INFO] [stderr]    Compiling rand_core v0.9.5
[INFO] [stderr]    Compiling serde_json v1.0.149
[INFO] [stderr]    Compiling rmp v0.8.15
[INFO] [stderr]    Compiling chacha20 v0.10.0
[INFO] [stderr]    Compiling signature v2.2.0
[INFO] [stderr]    Compiling indexmap v2.13.0
[INFO] [stderr]    Compiling cc v1.2.56
[INFO] [stderr]    Compiling ed25519 v2.2.3
[INFO] [stderr]    Compiling rustls-native-certs v0.8.3
[INFO] [stderr]    Compiling data-encoding v2.10.0
[INFO] [stderr]    Compiling uuid v1.21.0
[INFO] [stderr]    Compiling rand v0.10.0
[INFO] [stderr]    Compiling webpki-roots v0.26.11
[INFO] [stderr]    Compiling dashmap v6.1.0
[INFO] [stderr]    Compiling rustls-pemfile v2.2.0
[INFO] [stderr]    Compiling crypto-common v0.1.6
[INFO] [stderr]    Compiling block-buffer v0.10.4
[INFO] [stderr]    Compiling digest v0.10.7
[INFO] [stderr]    Compiling sha1 v0.10.6
[INFO] [stderr]    Compiling sha2 v0.10.9
[INFO] [stderr]    Compiling cmake v0.1.57
[INFO] [stderr]    Compiling toml_parser v1.0.9+spec-1.1.0
[INFO] [stderr]    Compiling aws-lc-sys v0.37.1
[INFO] [stderr]    Compiling serde_spanned v1.0.4
[INFO] [stderr]    Compiling toml_datetime v1.0.0+spec-1.1.0
[INFO] [stderr]    Compiling toml v1.0.3+spec-1.1.0
[INFO] [stderr]    Compiling synstructure v0.13.2
[INFO] [stderr]    Compiling nautilus-core v0.54.0
[INFO] [stderr]    Compiling ppv-lite86 v0.2.21
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling zerofrom-derive v0.1.6
[INFO] [stderr]    Compiling yoke-derive v0.8.1
[INFO] [stderr]    Compiling zerovec-derive v0.11.2
[INFO] [stderr]    Compiling displaydoc v0.2.5
[INFO] [stderr]    Compiling tokio-macros v2.6.1
[INFO] [stderr]    Compiling futures-macro v0.3.32
[INFO] [stderr]    Compiling rand_chacha v0.9.0
[INFO] [stderr]    Compiling thiserror-impl v2.0.18
[INFO] [stderr]    Compiling curve25519-dalek-derive v0.1.1
[INFO] [stderr]    Compiling strum_macros v0.28.0
[INFO] [stderr]    Compiling rand v0.9.2
[INFO] [stderr]    Compiling curve25519-dalek v4.1.3
[INFO] [stderr]    Compiling futures-util v0.3.32
[INFO] [stderr]    Compiling zerofrom v0.1.6
[INFO] [stderr]    Compiling yoke v0.8.1
[INFO] [stderr]    Compiling thiserror v2.0.18
[INFO] [stderr]    Compiling zerovec v0.11.5
[INFO] [stderr]    Compiling zerotrie v0.2.3
[INFO] [stderr]    Compiling tinystr v0.8.2
[INFO] [stderr]    Compiling potential_utf v0.1.4
[INFO] [stderr]    Compiling icu_collections v2.1.1
[INFO] [stderr]    Compiling icu_locale_core v2.1.1
[INFO] [stderr]    Compiling ed25519-dalek v2.2.0
[INFO] [stderr]    Compiling strum v0.28.0
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling icu_provider v2.1.1
[INFO] [stderr]    Compiling icu_properties v2.1.2
[INFO] [stderr]    Compiling icu_normalizer v2.1.1
[INFO] [stderr]    Compiling bytes v1.11.1
[INFO] [stderr]    Compiling ahash v0.8.12
[INFO] [stderr]    Compiling rmp-serde v1.3.1
[INFO] [stderr]    Compiling chrono v0.4.44
[INFO] [stderr]    Compiling serde_urlencoded v0.7.1
[INFO] [stderr]    Compiling ustr v1.1.0
[INFO] [stderr]    Compiling futures v0.3.32
[INFO] [stderr]    Compiling idna_adapter v1.2.1
[INFO] [stderr]    Compiling http v1.4.0
[INFO] [stderr]    Compiling tokio v1.49.0
[INFO] [stderr]    Compiling idna v1.1.0
[INFO] [stderr]    Compiling url v2.5.8
[INFO] [stderr]    Compiling http-body v1.0.1
[INFO] [stderr]    Compiling http-body-util v0.1.3
[INFO] [stderr]    Compiling hyper v1.8.1
[INFO] [stderr]    Compiling tower v0.5.3
[INFO] [stderr]    Compiling tokio-util v0.7.18
[INFO] [stderr]    Compiling tower-http v0.6.8
[INFO] [stderr]    Compiling hyper-util v0.1.20
[INFO] [stderr]    Compiling rustls-webpki v0.103.9
[INFO] [stderr]    Compiling tokio-rustls v0.26.4
[INFO] [stderr]    Compiling rustls-platform-verifier v0.6.2
[INFO] [stderr]    Compiling tungstenite v0.28.0
[INFO] [stderr]    Compiling hyper-rustls v0.27.7
[INFO] [stderr]    Compiling reqwest v0.13.2
[INFO] [stderr]    Compiling tokio-tungstenite v0.28.0
[INFO] [stderr]    Compiling nautilus-cryptography v0.54.0
[INFO] [stderr]    Compiling nautilus-network v0.54.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 40.22s
[INFO] running `Command { std: "docker" "inspect" "cfbf5fcfd3189e5cfc2c9cf2a2834531e14c9f5cb2a976376dfd1bea83323e97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cfbf5fcfd3189e5cfc2c9cf2a2834531e14c9f5cb2a976376dfd1bea83323e97", kill_on_drop: false }`
[INFO] [stdout] cfbf5fcfd3189e5cfc2c9cf2a2834531e14c9f5cb2a976376dfd1bea83323e97
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] c843a16dcf44e6c84d4dd4cb7e978240880ef52e7435d4ee5d604fa4de74bd7f
[INFO] running `Command { std: "docker" "start" "-a" "c843a16dcf44e6c84d4dd4cb7e978240880ef52e7435d4ee5d604fa4de74bd7f", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling serde_core v1.0.228
[INFO] [stderr]    Compiling zerocopy v0.8.40
[INFO] [stderr]    Compiling libm v0.2.16
[INFO] [stderr]    Compiling num-traits v0.2.19
[INFO] [stderr]    Compiling winnow v0.7.14
[INFO] [stderr]    Compiling prettyplease v0.2.37
[INFO] [stderr]    Compiling aho-corasick v1.1.4
[INFO] [stderr]    Compiling indexmap v2.13.0
[INFO] [stderr]    Compiling toml_datetime v0.7.5+spec-1.1.0
[INFO] [stderr]    Compiling rstest_macros v0.26.1
[INFO] [stderr]    Compiling proc-macro-error-attr2 v2.0.0
[INFO] [stderr]    Compiling implied-vol v2.0.0
[INFO] [stderr]    Compiling relative-path v1.9.3
[INFO] [stderr]    Compiling bytecount v0.6.9
[INFO] [stderr]    Compiling nautilus-model v0.54.0
[INFO] [stderr]    Compiling papergrid v0.17.0
[INFO] [stderr]    Compiling futures-timer v3.0.3
[INFO] [stderr]    Compiling regex-automata v0.4.14
[INFO] [stderr]    Compiling alloca v0.4.0
[INFO] [stderr]    Compiling evalexpr v11.3.1
[INFO] [stderr]    Compiling itertools v0.13.0
[INFO] [stderr]    Compiling clap_builder v4.5.60
[INFO] [stderr]    Compiling arraydeque v0.5.1
[INFO] [stderr]    Compiling nautilus-common v0.54.0
[INFO] [stderr]    Compiling rand_xorshift v0.4.0
[INFO] [stderr]    Compiling page_size v0.6.0
[INFO] [stderr]    Compiling sysinfo v0.38.3
[INFO] [stderr]    Compiling matchit v0.8.4
[INFO] [stderr]    Compiling tempfile v3.26.0
[INFO] [stderr]    Compiling log v0.4.29
[INFO] [stderr]    Compiling serde_json v1.0.149
[INFO] [stderr]    Compiling uuid v1.21.0
[INFO] [stderr]    Compiling serde_path_to_error v0.1.20
[INFO] [stderr]    Compiling toml_parser v1.0.9+spec-1.1.0
[INFO] [stderr]    Compiling criterion-plot v0.8.2
[INFO] [stderr]    Compiling rustls v0.23.37
[INFO] [stderr]    Compiling rmp v0.8.15
[INFO] [stderr]    Compiling toml v1.0.3+spec-1.1.0
[INFO] [stderr]    Compiling toml_edit v0.23.10+spec-1.0.0
[INFO] [stderr]    Compiling regex v1.12.3
[INFO] [stderr]    Compiling clap v4.5.60
[INFO] [stderr]    Compiling proc-macro-crate v3.4.0
[INFO] [stderr]    Compiling nautilus-core v0.54.0
[INFO] [stderr]    Compiling synstructure v0.13.2
[INFO] [stderr]    Compiling darling_core v0.20.11
[INFO] [stderr]    Compiling darling_core v0.23.0
[INFO] [stderr]    Compiling proc-macro-error2 v2.0.1
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling zerocopy-derive v0.8.40
[INFO] [stderr]    Compiling zerofrom-derive v0.1.6
[INFO] [stderr]    Compiling yoke-derive v0.8.1
[INFO] [stderr]    Compiling futures-macro v0.3.32
[INFO] [stderr]    Compiling tokio-macros v2.6.1
[INFO] [stderr]    Compiling zerovec-derive v0.11.2
[INFO] [stderr]    Compiling displaydoc v0.2.5
[INFO] [stderr]    Compiling thiserror-impl v2.0.18
[INFO] [stderr]    Compiling tracing-attributes v0.1.31
[INFO] [stderr]    Compiling strum_macros v0.28.0
[INFO] [stderr]    Compiling curve25519-dalek-derive v0.1.1
[INFO] [stderr]    Compiling tabled_derive v0.11.0
[INFO] [stderr]    Compiling futures-util v0.3.32
[INFO] [stderr]    Compiling enum_dispatch v0.3.13
[INFO] [stderr]    Compiling rust_decimal_macros v1.40.0
[INFO] [stderr]    Compiling curve25519-dalek v4.1.3
[INFO] [stderr]    Compiling tracing v0.1.44
[INFO] [stderr] error: could not compile `rustls` (lib)
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/562dee4820c458d823175268e41601d4c060588a/bin/rustc --crate-name rustls --edition=2021 /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/rustls-0.23.37/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --warn=unexpected_cfgs --check-cfg 'cfg(bench)' --check-cfg 'cfg(coverage_nightly)' --check-cfg 'cfg(read_buf)' --check-cfg 'cfg(rustls_docsrs)' --cfg 'feature="aws-lc-rs"' --cfg 'feature="aws_lc_rs"' --cfg 'feature="log"' --cfg 'feature="logging"' --cfg 'feature="std"' --cfg 'feature="tls12"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("aws-lc-rs", "aws_lc_rs", "brotli", "custom-provider", "default", "fips", "hashbrown", "log", "logging", "prefer-post-quantum", "read_buf", "ring", "rustversion", "std", "tls12", "zlib"))' -C metadata=ef8614c4b133e19d -C extra-filename=-64f9f9e1a2c7fb4f --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern aws_lc_rs=/opt/rustwide/target/debug/deps/libaws_lc_rs-4965ab4bbfdd0d13.rmeta --extern log=/opt/rustwide/target/debug/deps/liblog-a91796ff7cb2d874.rmeta --extern once_cell=/opt/rustwide/target/debug/deps/libonce_cell-0ba6aecba7086d38.rmeta --extern pki_types=/opt/rustwide/target/debug/deps/librustls_pki_types-43396bc1bdb4df85.rmeta --extern webpki=/opt/rustwide/target/debug/deps/libwebpki-0932c07caa7c489e.rmeta --extern subtle=/opt/rustwide/target/debug/deps/libsubtle-ca7024fc66e4388f.rmeta --extern zeroize=/opt/rustwide/target/debug/deps/libzeroize-36c98e1e0ab441af.rmeta --cap-lints allow --cap-lints=forbid -L native=/opt/rustwide/target/debug/build/aws-lc-sys-32494ec25b37efbd/out` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "c843a16dcf44e6c84d4dd4cb7e978240880ef52e7435d4ee5d604fa4de74bd7f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c843a16dcf44e6c84d4dd4cb7e978240880ef52e7435d4ee5d604fa4de74bd7f", kill_on_drop: false }`
[INFO] [stdout] c843a16dcf44e6c84d4dd4cb7e978240880ef52e7435d4ee5d604fa4de74bd7f