[INFO] cloning repository https://github.com/Fedomn/rust-knowledge
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Fedomn/rust-knowledge" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFedomn%2Frust-knowledge", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFedomn%2Frust-knowledge'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ebf59c0f558e79d311e340dbfd61409adb40eaa7
[INFO] testing Fedomn/rust-knowledge against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FFedomn%2Frust-knowledge" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Fedomn/rust-knowledge on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-7/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/Fedomn/rust-knowledge
[INFO] finished tweaking git repo https://github.com/Fedomn/rust-knowledge
[INFO] tweaked toml for git repo https://github.com/Fedomn/rust-knowledge written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/Fedomn/rust-knowledge already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9186d9f87bb367ae4a5799ea745c4cf4f0b89a48ddfd6e7267fce06bf9dc947b
[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" "9186d9f87bb367ae4a5799ea745c4cf4f0b89a48ddfd6e7267fce06bf9dc947b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9186d9f87bb367ae4a5799ea745c4cf4f0b89a48ddfd6e7267fce06bf9dc947b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9186d9f87bb367ae4a5799ea745c4cf4f0b89a48ddfd6e7267fce06bf9dc947b", kill_on_drop: false }`
[INFO] [stdout] 9186d9f87bb367ae4a5799ea745c4cf4f0b89a48ddfd6e7267fce06bf9dc947b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 124c90bba3343e1006e9ee995e6f3db170555748f9df4c374cdd7ee3038aae57
[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" "124c90bba3343e1006e9ee995e6f3db170555748f9df4c374cdd7ee3038aae57", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling web_server v0.1.0 (/opt/rustwide/workdir/web_server)
[INFO] [stderr]    Compiling command_line v0.1.0 (/opt/rustwide/workdir/command_line)
[INFO] [stderr]    Compiling time v0.1.44
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling rust-knowledge v0.1.0 (/opt/rustwide/workdir/playground)
[INFO] [stdout] warning: function is never used: `longest`
[INFO] [stdout]  --> playground/src/lifetimes.rs:6:4
[INFO] [stdout]   |
[INFO] [stdout] 6 | fn longest<'a, T>(x: &'a str, y: &'a str, ann: T) -> &'a str
[INFO] [stdout]   |    ^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.56s
[INFO] running `Command { std: "docker" "inspect" "124c90bba3343e1006e9ee995e6f3db170555748f9df4c374cdd7ee3038aae57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "124c90bba3343e1006e9ee995e6f3db170555748f9df4c374cdd7ee3038aae57", kill_on_drop: false }`
[INFO] [stdout] 124c90bba3343e1006e9ee995e6f3db170555748f9df4c374cdd7ee3038aae57
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 354d1a7eb04b6e746e965f3c0d9304e22052370f03df53be35e12f41dd0fa5b2
[INFO] running `Command { std: "docker" "start" "-a" "354d1a7eb04b6e746e965f3c0d9304e22052370f03df53be35e12f41dd0fa5b2", kill_on_drop: false }`
[INFO] [stderr]    Compiling command_line v0.1.0 (/opt/rustwide/workdir/command_line)
[INFO] [stderr]    Compiling web_server v0.1.0 (/opt/rustwide/workdir/web_server)
[INFO] [stderr]    Compiling rust-knowledge v0.1.0 (/opt/rustwide/workdir/playground)
[INFO] [stdout] warning: field is never read: `name`
[INFO] [stdout]   --> playground/src/basic.rs:79:13
[INFO] [stdout]    |
[INFO] [stdout] 79 |             name: String,
[INFO] [stdout]    |             ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `age`
[INFO] [stdout]   --> playground/src/basic.rs:80:13
[INFO] [stdout]    |
[INFO] [stdout] 80 |             age: i16,
[INFO] [stdout]    |             ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `username`
[INFO] [stdout]  --> playground/src/structs.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         username: String,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `email`
[INFO] [stdout]  --> playground/src/structs.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |         email: String,
[INFO] [stdout]   |         ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `sign_in_count`
[INFO] [stdout]  --> playground/src/structs.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |         sign_in_count: u64,
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `active`
[INFO] [stdout]  --> playground/src/structs.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 |         active: bool,
[INFO] [stdout]   |         ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `value`
[INFO] [stdout]    --> playground/src/wrapper_type.rs:103:9
[INFO] [stdout]     |
[INFO] [stdout] 103 |         value: i32,
[INFO] [stdout]     |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `children`
[INFO] [stdout]    --> playground/src/wrapper_type.rs:104:9
[INFO] [stdout]     |
[INFO] [stdout] 104 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 3.29s
[INFO] running `Command { std: "docker" "inspect" "354d1a7eb04b6e746e965f3c0d9304e22052370f03df53be35e12f41dd0fa5b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "354d1a7eb04b6e746e965f3c0d9304e22052370f03df53be35e12f41dd0fa5b2", kill_on_drop: false }`
[INFO] [stdout] 354d1a7eb04b6e746e965f3c0d9304e22052370f03df53be35e12f41dd0fa5b2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+722e1797249a965b6335aebd65d777f917e498f1" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 6f1006cecc37047c13536af06a035a60e7c457d55b04c03f7ade8e0e76e7d526
[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" "6f1006cecc37047c13536af06a035a60e7c457d55b04c03f7ade8e0e76e7d526", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: field is never read: `name`
[INFO] [stdout] running 3 tests
[INFO] [stderr]   --> playground/src/basic.rs:79:13
[INFO] [stdout] test tests::case_sensitive ... ok
[INFO] [stderr]    |
[INFO] [stdout] test tests::one_result ... ok
[INFO] [stderr] 79 |             name: String,
[INFO] [stdout] test tests::case_insensitive ... ok
[INFO] [stderr]    |             ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 3 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `age`
[INFO] [stderr]   --> playground/src/basic.rs:80:13
[INFO] [stderr]    |
[INFO] [stderr] 80 |             age: i16,
[INFO] [stderr]    |             ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `username`
[INFO] [stderr]  --> playground/src/structs.rs:6:9
[INFO] [stderr]   |
[INFO] [stderr] 6 |         username: String,
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `email`
[INFO] [stderr]  --> playground/src/structs.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |         email: String,
[INFO] [stderr]   |         ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `sign_in_count`
[INFO] [stderr]  --> playground/src/structs.rs:8:9
[INFO] [stderr]   |
[INFO] [stderr] 8 |         sign_in_count: u64,
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `active`
[INFO] [stderr]  --> playground/src/structs.rs:9:9
[INFO] [stderr]   |
[INFO] [stderr] 9 |         active: bool,
[INFO] [stderr]   |         ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `value`
[INFO] [stderr]    --> playground/src/wrapper_type.rs:103:9
[INFO] [stderr]     |
[INFO] [stderr] 103 |         value: i32,
[INFO] [stderr]     |         ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `children`
[INFO] [stderr]    --> playground/src/wrapper_type.rs:104:9
[INFO] [stderr]     |
[INFO] [stderr] 104 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rust-knowledge` (bin "rust-knowledge" test) generated 8 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/command_line-18ea6abdc9d59026)
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/command_line-416edca6dcf81728)
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust_knowledge-4f952dde8f5ec7c4)
[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; finished in 0.00s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 41 tests
[INFO] [stdout] test basic::basic::array ... ok
[INFO] [stdout] test concurrency::concurrency::mutex ... ok
[INFO] [stdout] test enums::enum_match ... ok
[INFO] [stdout] test basic::basic::function ... ok
[INFO] [stdout] test concurrency::concurrency::mpsc ... ok
[INFO] [stdout] test constant::constant::constfn_test ... ok
[INFO] [stdout] test basic::basic::control_flow ... ok
[INFO] [stdout] test basic::basic::string ... ok
[INFO] [stdout] test error::err::ignore_err ... ok
[INFO] [stdout] test concurrency::concurrency::spawn ... ok
[INFO] [stdout] test basic::basic::tuple ... ok
[INFO] [stdout] test basic::basic::variable ... ok
[INFO] [stdout] test basic::basic::object ... ok
[INFO] [stdout] test error::err::propagate_err ... ok
[INFO] [stdout] test lifetimes::lifetime_constraints ... ok
[INFO] [stdout] test enums::option ... ok
[INFO] [stdout] test basic::basic::map ... ok
[INFO] [stdout] test ownership::ownership::scope ... ok
[INFO] [stdout] test ownership::ownership::scope_reference ... ok
[INFO] [stdout] test basic::basic::stream ... ok
[INFO] [stdout] test ownership::ownership::string ... ok
[INFO] [stdout] test error::err::boxed_err ... ok
[INFO] [stdout] test basic::basic::pattern_match ... ok
[INFO] [stdout] test wrapper_type::wrapper_type::deref_test ... ok
[INFO] [stdout] test wrapper_type::wrapper_type::rc_test ... ok
[INFO] [stdout] test wrapper_type::wrapper_type::refcell_test ... ok
[INFO] [stdout] test basic::basic::destructuring ... ok
[INFO] [stdout] test error::err::fallback_err ... ok
[INFO] [stdout] test structs::tuple_structs ... ok
[INFO] [stdout] test error::err::terminate_err ... ok
[INFO] [stdout] test concurrency::concurrency::mutex_shared_in_multi_threads ... ok
[INFO] [stdout] test lifetimes::static_test ... ok
[INFO] [stdout] test wrapper_type::wrapper_type::box_recursive_type ... ok
[INFO] [stdout] test lifetimes::lifetime_reference ... ok
[INFO] [stdout] test structs::basic ... ok
[INFO] [stdout] test structs::method ... ok
[INFO] [stdout] test ownership::ownership::scope_move ... ok
[INFO] [stdout] test error::err::custom_err ... ok
[INFO] [stdout] test lifetimes::lifetime_annotations ... ok
[INFO] [stdout] test ownership::ownership::scope_func ... ok
[INFO] [stdout] test lifetimes::test1 ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 41 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
[INFO] [stdout] 
[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; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/web_server-8e4bc22cefc88314)
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/web_server-8f1fccf5803e7b06)
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests command_line
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[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; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests web_server
[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; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "6f1006cecc37047c13536af06a035a60e7c457d55b04c03f7ade8e0e76e7d526", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f1006cecc37047c13536af06a035a60e7c457d55b04c03f7ade8e0e76e7d526", kill_on_drop: false }`
[INFO] [stdout] 6f1006cecc37047c13536af06a035a60e7c457d55b04c03f7ade8e0e76e7d526