[INFO] crate promiser 0.0.5 is already in cache [INFO] testing promiser-0.0.5 against try#03a1ea71b075ab964b5278bc6e74cd6c52c36ee0 for pr-74409 [INFO] extracting crate promiser 0.0.5 into /workspace/builds/worker-9/source [INFO] validating manifest of crates.io crate promiser 0.0.5 on toolchain 03a1ea71b075ab964b5278bc6e74cd6c52c36ee0 [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] started tweaking crates.io crate promiser 0.0.5 [INFO] finished tweaking crates.io crate promiser 0.0.5 [INFO] tweaked toml for crates.io crate promiser 0.0.5 written to /workspace/builds/worker-9/source/Cargo.toml [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }` [INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] d4816ba4ef1ae313bd137377b70eb8a41ba14f05eba2c63684193a3662110ec9 [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" "d4816ba4ef1ae313bd137377b70eb8a41ba14f05eba2c63684193a3662110ec9", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "d4816ba4ef1ae313bd137377b70eb8a41ba14f05eba2c63684193a3662110ec9", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "d4816ba4ef1ae313bd137377b70eb8a41ba14f05eba2c63684193a3662110ec9", kill_on_drop: false }` [INFO] [stdout] d4816ba4ef1ae313bd137377b70eb8a41ba14f05eba2c63684193a3662110ec9 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "build" "--frozen" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 774d75e92c790ec253cb49bc883ed1d35d2e7405b3174f4094c5ed8eb53414d7 [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" "774d75e92c790ec253cb49bc883ed1d35d2e7405b3174f4094c5ed8eb53414d7", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.73 [INFO] [stderr] Compiling rand v0.4.6 [INFO] [stderr] Compiling rand v0.3.23 [INFO] [stderr] Compiling promiser v0.0.5 (/opt/rustwide/workdir) [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 4.07s [INFO] running `Command { std: "docker" "inspect" "774d75e92c790ec253cb49bc883ed1d35d2e7405b3174f4094c5ed8eb53414d7", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "774d75e92c790ec253cb49bc883ed1d35d2e7405b3174f4094c5ed8eb53414d7", kill_on_drop: false }` [INFO] [stdout] 774d75e92c790ec253cb49bc883ed1d35d2e7405b3174f4094c5ed8eb53414d7 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 37dec7574b569c6db194ea2cab9f64df58ae48726f99516bd238802fa1123e7b [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" "37dec7574b569c6db194ea2cab9f64df58ae48726f99516bd238802fa1123e7b", kill_on_drop: false }` [INFO] [stderr] Compiling promiser v0.0.5 (/opt/rustwide/workdir) [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 1.15s [INFO] running `Command { std: "docker" "inspect" "37dec7574b569c6db194ea2cab9f64df58ae48726f99516bd238802fa1123e7b", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "37dec7574b569c6db194ea2cab9f64df58ae48726f99516bd238802fa1123e7b", kill_on_drop: false }` [INFO] [stdout] 37dec7574b569c6db194ea2cab9f64df58ae48726f99516bd238802fa1123e7b [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "test" "--frozen", kill_on_drop: false }` [INFO] [stdout] 34878b231d123bd96c9584642627ba6af9767ef7b5e3bb78ac834267dff883a6 [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" "34878b231d123bd96c9584642627ba6af9767ef7b5e3bb78ac834267dff883a6", kill_on_drop: false }` [INFO] [stderr] Finished test [unoptimized + debuginfo] target(s) in 0.02s [INFO] [stderr] Running /opt/rustwide/target/debug/deps/promiser-7a81ace6f124b948 [INFO] [stdout] [INFO] [stdout] running 5 tests [INFO] [stderr] thread '' panicked at 'proc dead', src/promise.rs:221:17 [INFO] [stdout] test promise::tests::test_promise_linear ... ok [INFO] [stderr] stack backtrace: [INFO] [stdout] test promise::tests::test_promise_threaded_panic_safely2 ... ok [INFO] [stderr] thread '' panicked at 'proc dead', src/promise.rs:234:17 [INFO] [stdout] test latch::tests::test_latch ... ok [INFO] [stdout] test promise::tests::test_promise_threaded ... ok [INFO] [stderr] 0: 0x556041548695 - backtrace::backtrace::libunwind::trace::hea89dfbbfe67f40d [INFO] [stderr] at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86 [INFO] [stderr] 1: 0x556041548695 - backtrace::backtrace::trace_unsynchronized::h0513dd713d7644d4 [INFO] [stderr] at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66 [INFO] [stderr] 2: 0x556041548695 - std::sys_common::backtrace::_print_fmt::h040abae64e4a24a9 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:78 [INFO] [stderr] 3: 0x556041548695 - ::fmt::hb4bdb37c3c335733 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:59 [INFO] [stderr] 4: 0x55604157035c - core::fmt::write::h540ac4a6a1232abc [INFO] [stderr] at src/libcore/fmt/mod.rs:1076 [INFO] [stderr] 5: 0x556041544f82 - std::io::Write::write_fmt::h5ffa1b5a7703af47 [INFO] [stderr] at src/libstd/io/mod.rs:1539 [INFO] [stderr] 6: 0x55604154adf0 - std::sys_common::backtrace::_print::hb55cc635eaf1882e [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:62 [INFO] [stderr] 7: 0x55604154adf0 - std::sys_common::backtrace::print::h2b2218fa55714084 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:49 [INFO] [stderr] 8: 0x55604154adf0 - std::panicking::default_hook::{{closure}}::h578517c025765cf3 [INFO] [stderr] at src/libstd/panicking.rs:198 [INFO] [stderr] 9: 0x55604154ab3c - std::panicking::default_hook::h4cafc94c2fc640fb [INFO] [stderr] at src/libstd/panicking.rs:217 [INFO] [stderr] 10: 0x55604154b433 - std::panicking::rust_panic_with_hook::h3eeb5001beeca5c3 [INFO] [stderr] at src/libstd/panicking.rs:526 [INFO] [stderr] 11: 0x556041536a49 - std::panicking::begin_panic::h5c9f9a898cb04733 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:456 [INFO] [stderr] 12: 0x5560414e3817 - promiser::promise::tests::test_promise_threaded_panic_safely::{{closure}}::hf2b4ef7b2c24e4dd [INFO] [stderr] at src/promise.rs:221 [INFO] [stderr] 13: 0x5560414e7e90 - std::sys_common::backtrace::__rust_begin_short_backtrace::hdead6b6553c62daa [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/sys_common/backtrace.rs:130 [INFO] [stderr] 14: 0x5560414e57a0 - std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}::hd360dad11e918ae0 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/thread/mod.rs:475 [INFO] [stderr] 15: 0x5560414f63e2 - as core::ops::function::FnOnce<()>>::call_once::he1fb2df883b2327b [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panic.rs:318 [INFO] [stderr] 16: 0x5560414e8329 - std::panicking::try::do_call::h70963b39be92ca3d [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:348 [INFO] [stderr] 17: 0x5560414eaf0d - __rust_try [INFO] [stderr] 18: 0x5560414e7f60 - std::panicking::try::h862cb07acd6a8256 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:325 [INFO] [stderr] 19: 0x5560414f68d2 - std::panic::catch_unwind::h192a5721395c83dc [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panic.rs:394 [INFO] [stderr] 20: 0x5560414e4f09 - std::thread::Builder::spawn_unchecked::{{closure}}::h324af3899d67f970 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/thread/mod.rs:474 [INFO] [stderr] 21: 0x5560414e874e - core::ops::function::FnOnce::call_once{{vtable.shim}}::hef7ad2634ac54d53 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libcore/ops/function.rs:233 [INFO] [stderr] 22: 0x55604155165a - as core::ops::function::FnOnce>::call_once::hc0e15d78a519721e [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/liballoc/boxed.rs:1081 [INFO] [stderr] 23: 0x55604155165a - as core::ops::function::FnOnce>::call_once::h211da8fffb09f192 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/liballoc/boxed.rs:1081 [INFO] [stderr] 24: 0x55604155165a - std::sys::unix::thread::Thread::new::thread_start::h29594ddebf23e421 [INFO] [stderr] at src/libstd/sys/unix/thread.rs:87 [INFO] [stderr] 25: 0x7f8651cfd609 - start_thread [INFO] [stderr] 26: 0x7f8651c09103 - __clone [INFO] [stderr] 27: 0x0 - [INFO] [stderr] stack backtrace: [INFO] [stderr] 0: 0x556041548695 - backtrace::backtrace::libunwind::trace::hea89dfbbfe67f40d [INFO] [stderr] at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86 [INFO] [stderr] 1: 0x556041548695 - backtrace::backtrace::trace_unsynchronized::h0513dd713d7644d4 [INFO] [stderr] at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66 [INFO] [stderr] 2: 0x556041548695 - std::sys_common::backtrace::_print_fmt::h040abae64e4a24a9 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:78 [INFO] [stderr] 3: 0x556041548695 - ::fmt::hb4bdb37c3c335733 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:59 [INFO] [stderr] 4: 0x55604157035c - core::fmt::write::h540ac4a6a1232abc [INFO] [stderr] at src/libcore/fmt/mod.rs:1076 [INFO] [stderr] 5: 0x556041544f82 - std::io::Write::write_fmt::h5ffa1b5a7703af47 [INFO] [stderr] at src/libstd/io/mod.rs:1539 [INFO] [stderr] 6: 0x55604154adf0 - std::sys_common::backtrace::_print::hb55cc635eaf1882e [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:62 [INFO] [stderr] 7: 0x55604154adf0 - std::sys_common::backtrace::print::h2b2218fa55714084 [INFO] [stderr] at src/libstd/sys_common/backtrace.rs:49 [INFO] [stderr] 8: 0x55604154adf0 - std::panicking::default_hook::{{closure}}::h578517c025765cf3 [INFO] [stderr] at src/libstd/panicking.rs:198 [INFO] [stderr] 9: 0x55604154ab3c - std::panicking::default_hook::h4cafc94c2fc640fb [INFO] [stderr] at src/libstd/panicking.rs:217 [INFO] [stderr] 10: 0x55604154b433 - std::panicking::rust_panic_with_hook::h3eeb5001beeca5c3 [INFO] [stderr] at src/libstd/panicking.rs:526 [INFO] [stderr] 11: 0x556041536a49 - std::panicking::begin_panic::h5c9f9a898cb04733 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:456 [INFO] [stderr] 12: 0x5560414e3a17 - promiser::promise::tests::test_promise_threaded_panic_safely2::{{closure}}::he60b30511803ecc9 [INFO] [stderr] at src/promise.rs:234 [INFO] [stderr] 13: 0x5560414e7e50 - std::sys_common::backtrace::__rust_begin_short_backtrace::h70fc85c9d3274183 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/sys_common/backtrace.rs:130 [INFO] [stderr] 14: 0x5560414e5720 - std::thread::Builder::spawn_unchecked::{{closure}}::{{closure}}::h14ad9ed4dfa73c88 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/thread/mod.rs:475 [INFO] [stderr] 15: 0x5560414f6362 - as core::ops::function::FnOnce<()>>::call_once::h321e629d746243f1 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panic.rs:318 [INFO] [stderr] 16: 0x5560414e8399 - std::panicking::try::do_call::h8564fd47ecb3a312 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:348 [INFO] [stderr] 17: 0x5560414eaf0d - __rust_try [INFO] [stderr] 18: 0x5560414e80a0 - std::panicking::try::hb62c36c9d58ce2d9 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panicking.rs:325 [INFO] [stderr] 19: 0x5560414f6972 - std::panic::catch_unwind::hf79f5d590f5a4503 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/panic.rs:394 [INFO] [stderr] 20: 0x5560414e5529 - std::thread::Builder::spawn_unchecked::{{closure}}::hca4224b055ef44a9 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libstd/thread/mod.rs:474 [INFO] [stderr] 21: 0x5560414e876e - core::ops::function::FnOnce::call_once{{vtable.shim}}::hf6e9ff96e4a62099 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/libcore/ops/function.rs:233 [INFO] [stderr] 22: 0x55604155165a - as core::ops::function::FnOnce>::call_once::hc0e15d78a519721e [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/liballoc/boxed.rs:1081 [INFO] [stderr] 23: 0x55604155165a - as core::ops::function::FnOnce>::call_once::h211da8fffb09f192 [INFO] [stderr] at /rustc/03a1ea71b075ab964b5278bc6e74cd6c52c36ee0/src/liballoc/boxed.rs:1081 [INFO] [stderr] 24: 0x55604155165a - std::sys::unix::thread::Thread::new::thread_start::h29594ddebf23e421 [INFO] [stderr] at src/libstd/sys/unix/thread.rs:87 [INFO] [stderr] 25: 0x7f8651cfd609 - start_thread [INFO] [stderr] 26: 0x7f8651c09103 - __clone [INFO] [stderr] 27: 0x0 - [INFO] [stdout] test promise::tests::test_promise_threaded_panic_safely ... ok [INFO] [stdout] [INFO] [stdout] test result: ok. 5 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [INFO] [stdout] [INFO] [stderr] Doc-tests promiser [INFO] [stdout] [INFO] [stdout] running 0 tests [INFO] [stdout] [INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out [INFO] [stdout] [INFO] running `Command { std: "docker" "inspect" "34878b231d123bd96c9584642627ba6af9767ef7b5e3bb78ac834267dff883a6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "34878b231d123bd96c9584642627ba6af9767ef7b5e3bb78ac834267dff883a6", kill_on_drop: false }` [INFO] [stdout] 34878b231d123bd96c9584642627ba6af9767ef7b5e3bb78ac834267dff883a6