[INFO] cloning repository https://github.com/schnupperboy/bitcoin-micropayments [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/schnupperboy/bitcoin-micropayments" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fschnupperboy%2Fbitcoin-micropayments", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fschnupperboy%2Fbitcoin-micropayments'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] 2c9aa89bff6ce328e251856e6108e15bd73a1faf [INFO] testing schnupperboy/bitcoin-micropayments against try#8262275854dc0e5381c9d42d56257d94932c5a87 for pr-90799 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fschnupperboy%2Fbitcoin-micropayments" "/workspace/builds/worker-5/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/schnupperboy/bitcoin-micropayments on toolchain 8262275854dc0e5381c9d42d56257d94932c5a87 [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8262275854dc0e5381c9d42d56257d94932c5a87" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/schnupperboy/bitcoin-micropayments [INFO] finished tweaking git repo https://github.com/schnupperboy/bitcoin-micropayments [INFO] tweaked toml for git repo https://github.com/schnupperboy/bitcoin-micropayments written to /workspace/builds/worker-5/source/Cargo.toml [INFO] crate git repo https://github.com/schnupperboy/bitcoin-micropayments already has a lockfile, it will not be regenerated [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8262275854dc0e5381c9d42d56257d94932c5a87" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Updating git repository `https://github.com/kennytm/qrcode-rust` [INFO] [stderr] Downloading crates ... [INFO] [stderr] Downloaded cookie v0.2.2 [INFO] [stderr] Downloaded websocket v0.14.0 [INFO] [stderr] Downloaded num v0.1.28 [INFO] [stderr] Downloaded enum_primitive v0.1.0 [INFO] [stderr] Downloaded gif v0.6.0 [INFO] [stderr] Downloaded flate2 v0.2.11 [INFO] [stderr] Downloaded lzw v0.9.0 [INFO] [stderr] Downloaded gcc v0.3.20 [INFO] [stderr] Downloaded httparse v1.0.0 [INFO] [stderr] Downloaded inflate v0.1.0 [INFO] [stderr] Downloaded net2 v0.2.19 [INFO] [stderr] Downloaded image v0.5.4 [INFO] [stderr] Downloaded hyper v0.7.0 [INFO] [stderr] Downloaded serde v0.6.1 [INFO] [stderr] Downloaded url v0.5.0 [INFO] [stderr] Downloaded openssl v0.7.1 [INFO] [stderr] Downloaded openssl-sys v0.7.1 [INFO] [stderr] Downloaded openssl-sys-extras v0.7.1 [INFO] [stderr] Downloaded libc v0.2.2 [INFO] [stderr] Downloaded unicase v1.0.1 [INFO] [stderr] Downloaded miniz-sys v0.1.7 [INFO] [stderr] Downloaded color_quant v1.0.0 [INFO] [stderr] Downloaded regex v0.1.43 [INFO] [stderr] Downloaded language-tags v0.2.0 [INFO] [stderr] Downloaded aho-corasick v0.4.0 [INFO] [stderr] Downloaded regex_macros v0.1.24 [INFO] [stderr] Downloaded png v0.4.0 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+8262275854dc0e5381c9d42d56257d94932c5a87" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 3b07baade5a05afdad6e9b6f01da5a59592265a89c74041b693303759d22791d [INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap. [INFO] running `Command { std: "docker" "start" "-a" "3b07baade5a05afdad6e9b6f01da5a59592265a89c74041b693303759d22791d", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "3b07baade5a05afdad6e9b6f01da5a59592265a89c74041b693303759d22791d", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "3b07baade5a05afdad6e9b6f01da5a59592265a89c74041b693303759d22791d", kill_on_drop: false }` [INFO] [stdout] 3b07baade5a05afdad6e9b6f01da5a59592265a89c74041b693303759d22791d [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+8262275854dc0e5381c9d42d56257d94932c5a87" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] d48f93825e197bd6a01a067f25a25345c0205bb617048af585c7799f1f0ccc4f [INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap. [INFO] running `Command { std: "docker" "start" "-a" "d48f93825e197bd6a01a067f25a25345c0205bb617048af585c7799f1f0ccc4f", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.2 [INFO] [stderr] Compiling winapi-build v0.1.1 [INFO] [stderr] Compiling winapi v0.2.5 [INFO] [stderr] Compiling gcc v0.3.20 [INFO] [stderr] Compiling rustc-serialize v0.3.16 [INFO] [stderr] Compiling pkg-config v0.3.6 [INFO] [stderr] Compiling bitflags v0.3.3 [INFO] [stderr] Compiling matches v0.1.2 [INFO] [stderr] Compiling lazy_static v0.1.15 [INFO] [stderr] Compiling lzw v0.9.0 [INFO] [stderr] Compiling color_quant v1.0.0 [INFO] [stderr] Compiling traitobject v0.0.1 [INFO] [stderr] Compiling httparse v1.0.0 [INFO] [stderr] Compiling cfg-if v0.1.0 [INFO] [stderr] Compiling language-tags v0.2.0 [INFO] [stderr] Compiling regex-syntax v0.2.2 [INFO] [stderr] Compiling inflate v0.1.0 [INFO] [stderr] Compiling typeable v0.1.2 [INFO] [stderr] Compiling byteorder v0.4.2 [INFO] [stderr] Compiling unicase v1.0.1 [INFO] [stderr] Compiling glob v0.2.10 [INFO] [stdout] error[E0642]: patterns aren't allowed in functions without bodies [INFO] [stdout] --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/rustc-serialize-0.3.16/src/serialize.rs:145:45 [INFO] [stdout] | [INFO] [stdout] 145 | ... &f_name: &str, [INFO] [stdout] | ^^^^^^^ pattern not allowed in function without body [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Compiling advapi32-sys v0.1.2 [INFO] [stderr] Compiling kernel32-sys v0.2.1 [INFO] [stderr] Compiling ws2_32-sys v0.2.1 [INFO] [stderr] Compiling log v0.3.4 [INFO] [stderr] Compiling memchr v0.1.7 [INFO] [stderr] Compiling gif v0.6.0 [INFO] [stderr] Compiling aho-corasick v0.4.0 [INFO] [stderr] Compiling hpack v0.2.0 [INFO] [stderr] Compiling time v0.1.34 [INFO] [stderr] Compiling num_cpus v0.2.10 [INFO] [stderr] Compiling net2 v0.2.19 [INFO] [stderr] Compiling rand v0.3.12 [INFO] [stderr] Compiling openssl-sys v0.7.1 [INFO] [stderr] Compiling solicit v0.4.4 [INFO] [stderr] Compiling openssl-sys-extras v0.7.1 [INFO] [stderr] Compiling miniz-sys v0.1.7 [INFO] [stderr] Compiling regex v0.1.43 [INFO] [stderr] error: failed to run custom build command for `openssl-sys-extras v0.7.1` [INFO] [stderr] [INFO] [stderr] Caused by: [INFO] [stderr] process didn't exit successfully: `/opt/rustwide/target/debug/build/openssl-sys-extras-4e5daf0472349946/build-script-build` (exit status: 101) [INFO] [stderr] --- stdout [INFO] [stderr] TARGET = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] OPT_LEVEL = Some("0") [INFO] [stderr] PROFILE = Some("debug") [INFO] [stderr] TARGET = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] debug=true opt-level=0 [INFO] [stderr] HOST = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] TARGET = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] TARGET = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] HOST = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] CC_x86_64-unknown-linux-gnu = None [INFO] [stderr] CC_x86_64_unknown_linux_gnu = None [INFO] [stderr] HOST_CC = None [INFO] [stderr] CC = None [INFO] [stderr] HOST = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] TARGET = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] HOST = Some("x86_64-unknown-linux-gnu") [INFO] [stderr] CFLAGS_x86_64-unknown-linux-gnu = None [INFO] [stderr] CFLAGS_x86_64_unknown_linux_gnu = None [INFO] [stderr] HOST_CFLAGS = None [INFO] [stderr] CFLAGS = None [INFO] [stderr] running: "cc" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-m64" "-fPIC" "-o" "/opt/rustwide/target/debug/build/openssl-sys-extras-102d867c90153db6/out/src/openssl_shim.o" "-c" "src/openssl_shim.c" [INFO] [stderr] ExitStatus(unix_wait_status(256)) [INFO] [stderr] [INFO] [stderr] [INFO] [stderr] command did not execute successfully, got: exit status: 1 [INFO] [stderr] [INFO] [stderr] [INFO] [stderr] [INFO] [stderr] --- stderr [INFO] [stderr] src/openssl_shim.c: In function 'DH_new_from_params': [INFO] [stderr] src/openssl_shim.c:130:7: error: dereferencing pointer to incomplete type 'DH' {aka 'struct dh_st'} [INFO] [stderr] 130 | dh->p = p; [INFO] [stderr] | ^~ [INFO] [stderr] src/openssl_shim.c: In function 'X509_get_extensions_shim': [INFO] [stderr] src/openssl_shim.c:141:13: error: dereferencing pointer to incomplete type 'X509' {aka 'struct x509_st'} [INFO] [stderr] 141 | return x->cert_info ? x->cert_info->extensions : NULL; [INFO] [stderr] | ^~ [INFO] [stderr] thread 'main' panicked at 'explicit panic', /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/gcc-0.3.20/src/lib.rs:772:5 [INFO] [stderr] stack backtrace: [INFO] [stderr] 0: 0x5607988bf16c - std::backtrace_rs::backtrace::libunwind::trace::h793e05efd273d0f4 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5 [INFO] [stderr] 1: 0x5607988bf16c - std::backtrace_rs::backtrace::trace_unsynchronized::h640b7b86ff610c77 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5 [INFO] [stderr] 2: 0x5607988bf16c - std::sys_common::backtrace::_print_fmt::h362fa2a4f354f877 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:67:5 [INFO] [stderr] 3: 0x5607988bf16c - ::fmt::hf439e5ed84c74abd [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:46:22 [INFO] [stderr] 4: 0x5607988de4ac - core::fmt::write::h72801a82c94e6ff1 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/core/src/fmt/mod.rs:1149:17 [INFO] [stderr] 5: 0x5607988bb2f5 - std::io::Write::write_fmt::h5562a8b6da0f0339 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/io/mod.rs:1697:15 [INFO] [stderr] 6: 0x5607988c08b0 - std::sys_common::backtrace::_print::hb29ddd998d02631c [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:49:5 [INFO] [stderr] 7: 0x5607988c08b0 - std::sys_common::backtrace::print::h81965e3d7c90fbb6 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:36:9 [INFO] [stderr] 8: 0x5607988c08b0 - std::panicking::default_hook::{{closure}}::h84db205ab6674b38 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:211:50 [INFO] [stderr] 9: 0x5607988c045b - std::panicking::default_hook::h1bf8bb4159936bca [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:228:9 [INFO] [stderr] 10: 0x5607988c0f64 - std::panicking::rust_panic_with_hook::hf8e86850fbbd03b1 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:606:17 [INFO] [stderr] 11: 0x56079888d972 - std::panicking::begin_panic::{{closure}}::hdda4dcaf976e4d28 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:526:9 [INFO] [stderr] 12: 0x56079888ef09 - std::sys_common::backtrace::__rust_end_short_backtrace::h4c3f20d474ebbea5 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:139:18 [INFO] [stderr] 13: 0x56079888d8b3 - std::panicking::begin_panic::h99061881b50b36bb [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:525:12 [INFO] [stderr] 14: 0x5607988880e5 - gcc::fail::h6ad113db9eb072c7 [INFO] [stderr] at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/gcc-0.3.20/src/lib.rs:772:5 [INFO] [stderr] 15: 0x56079888801e - gcc::run::hb2b411071ec2a807 [INFO] [stderr] at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/gcc-0.3.20/src/lib.rs:766:9 [INFO] [stderr] 16: 0x560798881acd - gcc::Config::compile_object::h443a03c91cd7a7dd [INFO] [stderr] at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/gcc-0.3.20/src/lib.rs:364:9 [INFO] [stderr] 17: 0x560798880acd - gcc::Config::compile::h372bb168f20edf37 [INFO] [stderr] at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/gcc-0.3.20/src/lib.rs:319:13 [INFO] [stderr] 18: 0x56079887cd26 - build_script_build::main::h5e6c0ccb111a30fa [INFO] [stderr] at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/openssl-sys-extras-0.7.1/build.rs:19:5 [INFO] [stderr] 19: 0x56079887f9fb - core::ops::function::FnOnce::call_once::hf7316aafe2eae1e0 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/core/src/ops/function.rs:227:5 [INFO] [stderr] 20: 0x56079887e51e - std::sys_common::backtrace::__rust_begin_short_backtrace::hd473f118d8aa6e10 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/sys_common/backtrace.rs:123:18 [INFO] [stderr] 21: 0x56079887e5b1 - std::rt::lang_start::{{closure}}::h7746874ba1757e2b [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/rt.rs:145:18 [INFO] [stderr] 22: 0x5607988be9b1 - core::ops::function::impls:: for &F>::call_once::h42d3791e66d196c0 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/core/src/ops/function.rs:259:13 [INFO] [stderr] 23: 0x5607988be9b1 - std::panicking::try::do_call::hc3bcb188e535517f [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:406:40 [INFO] [stderr] 24: 0x5607988be9b1 - std::panicking::try::hb1edf04d4a7097ab [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:370:19 [INFO] [stderr] 25: 0x5607988be9b1 - std::panic::catch_unwind::h75ed941ac0d36d57 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panic.rs:133:14 [INFO] [stderr] 26: 0x5607988be9b1 - std::rt::lang_start_internal::{{closure}}::hc702b3389af4cbea [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/rt.rs:128:48 [INFO] [stderr] 27: 0x5607988be9b1 - std::panicking::try::do_call::h53276a03c7fe2ebc [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:406:40 [INFO] [stderr] 28: 0x5607988be9b1 - std::panicking::try::ha9e37f45dc542517 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panicking.rs:370:19 [INFO] [stderr] 29: 0x5607988be9b1 - std::panic::catch_unwind::h182647595766fee7 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/panic.rs:133:14 [INFO] [stderr] 30: 0x5607988be9b1 - std::rt::lang_start_internal::h571831ebdba142de [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/rt.rs:128:20 [INFO] [stderr] 31: 0x56079887e580 - std::rt::lang_start::hd21e37580490f3c2 [INFO] [stderr] at /rustc/8262275854dc0e5381c9d42d56257d94932c5a87/library/std/src/rt.rs:144:17 [INFO] [stderr] 32: 0x56079887de5c - main [INFO] [stderr] 33: 0x7f7748e850b3 - __libc_start_main [INFO] [stderr] 34: 0x56079887c8ae - _start [INFO] [stderr] 35: 0x0 - [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stdout] error[E0446]: private type `SingleSearch` in public interface [INFO] [stdout] --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/regex-0.1.43/src/prefix.rs:46:12 [INFO] [stdout] | [INFO] [stdout] 46 | Single(SingleSearch), [INFO] [stdout] | ^^^^^^^^^^^^ can't leak private type [INFO] [stdout] ... [INFO] [stdout] 169 | struct SingleSearch { [INFO] [stdout] | ------------------- `SingleSearch` declared as private [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error: aborting due to previous error [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] For more information about this error, try `rustc --explain E0446`. [INFO] [stdout] [INFO] [stdout] error: aborting due to previous error [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] For more information about this error, try `rustc --explain E0642`. [INFO] [stdout] [INFO] [stderr] error: build failed [INFO] running `Command { std: "docker" "inspect" "d48f93825e197bd6a01a067f25a25345c0205bb617048af585c7799f1f0ccc4f", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "d48f93825e197bd6a01a067f25a25345c0205bb617048af585c7799f1f0ccc4f", kill_on_drop: false }` [INFO] [stdout] d48f93825e197bd6a01a067f25a25345c0205bb617048af585c7799f1f0ccc4f