[INFO] fetching crate slog-extra 0.1.2...
[INFO] testing slog-extra-0.1.2 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate slog-extra 0.1.2 into /workspace/builds/worker-3-tc2/source
[INFO] started tweaking crates.io crate slog-extra 0.1.2
[INFO] finished tweaking crates.io crate slog-extra 0.1.2
[INFO] tweaked toml for crates.io crate slog-extra 0.1.2 written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate slog-extra 0.1.2 on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 3 packages to latest compatible versions
[INFO] [stderr]       Adding slog v1.7.1 (available: v2.8.2)
[INFO] [stderr]       Adding thread_local v0.3.6 (available: v1.1.9)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6d1fbed824f03a496ce297d24b85ac60cdeafd8a954106c91dc784281a31938a
[INFO] running `Command { std: "docker" "start" "-a" "6d1fbed824f03a496ce297d24b85ac60cdeafd8a954106c91dc784281a31938a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6d1fbed824f03a496ce297d24b85ac60cdeafd8a954106c91dc784281a31938a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6d1fbed824f03a496ce297d24b85ac60cdeafd8a954106c91dc784281a31938a", kill_on_drop: false }`
[INFO] [stdout] 6d1fbed824f03a496ce297d24b85ac60cdeafd8a954106c91dc784281a31938a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c46b706b4ec6ecfa3ebc079767fc8b7ac3cc0355fbc9114e4747c1984b5aa088
[INFO] running `Command { std: "docker" "start" "-a" "c46b706b4ec6ecfa3ebc079767fc8b7ac3cc0355fbc9114e4747c1984b5aa088", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling slog v1.7.1
[INFO] [stderr]    Compiling slog-extra v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:194:13
[INFO] [stdout]     |
[INFO] [stdout] 194 |             try!(v.serialize(record, k, &mut ser))
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:94:44
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<Serialize + Send>)>;
[INFO] [stdout]    |                                            ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<dyn Serialize + Send>)>;
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> lib.rs:222:43
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<Serialize + Send>)>,
[INFO] [stdout]     |                                           ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<dyn Serialize + Send>)>,
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:54:62
[INFO] [stdout]    |
[INFO] [stdout] 54 | ...                   .map(|&(k, ref v)| (k, v as &Serialize))
[INFO] [stdout]    |                                                    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 54 |                                 .map(|&(k, ref v)| (k, v as &dyn Serialize))
[INFO] [stdout]    |                                                              +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.59s
[INFO] running `Command { std: "docker" "inspect" "c46b706b4ec6ecfa3ebc079767fc8b7ac3cc0355fbc9114e4747c1984b5aa088", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c46b706b4ec6ecfa3ebc079767fc8b7ac3cc0355fbc9114e4747c1984b5aa088", kill_on_drop: false }`
[INFO] [stdout] c46b706b4ec6ecfa3ebc079767fc8b7ac3cc0355fbc9114e4747c1984b5aa088
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+beta-2026-04-21" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3db3e31c6c127ddf4ccf596c06245dce419f55f377cc4db2a743c0c5fa2816b0
[INFO] running `Command { std: "docker" "start" "-a" "3db3e31c6c127ddf4ccf596c06245dce419f55f377cc4db2a743c0c5fa2816b0", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling slog-extra v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:194:13
[INFO] [stdout]     |
[INFO] [stdout] 194 |             try!(v.serialize(record, k, &mut ser))
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:94:44
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<Serialize + Send>)>;
[INFO] [stdout]    |                                            ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<dyn Serialize + Send>)>;
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> lib.rs:222:43
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<Serialize + Send>)>,
[INFO] [stdout]     |                                           ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<dyn Serialize + Send>)>,
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:54:62
[INFO] [stdout]    |
[INFO] [stdout] 54 | ...                   .map(|&(k, ref v)| (k, v as &Serialize))
[INFO] [stdout]    |                                                    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 54 |                                 .map(|&(k, ref v)| (k, v as &dyn Serialize))
[INFO] [stdout]    |                                                              +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:194:13
[INFO] [stdout]     |
[INFO] [stdout] 194 |             try!(v.serialize(record, k, &mut ser))
[INFO] [stdout]     |             ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:94:44
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<Serialize + Send>)>;
[INFO] [stdout]    |                                            ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 94 | type RecordValues = Vec<(&'static str, Box<dyn Serialize + Send>)>;
[INFO] [stdout]    |                                            +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> lib.rs:222:43
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<Serialize + Send>)>,
[INFO] [stdout]     |                                           ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 222 |     record_values: Vec<(&'static str, Box<dyn Serialize + Send>)>,
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:54:62
[INFO] [stdout]    |
[INFO] [stdout] 54 | ...                   .map(|&(k, ref v)| (k, v as &Serialize))
[INFO] [stdout]    |                                                    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 54 |                                 .map(|&(k, ref v)| (k, v as &dyn Serialize))
[INFO] [stdout]    |                                                              +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.22s
[INFO] running `Command { std: "docker" "inspect" "3db3e31c6c127ddf4ccf596c06245dce419f55f377cc4db2a743c0c5fa2816b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3db3e31c6c127ddf4ccf596c06245dce419f55f377cc4db2a743c0c5fa2816b0", kill_on_drop: false }`
[INFO] [stdout] 3db3e31c6c127ddf4ccf596c06245dce419f55f377cc4db2a743c0c5fa2816b0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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" "+beta-2026-04-21" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 940aa81e4786202e302f066f71e84171f818c79cc472f00fed04e6f3b027d081
[INFO] running `Command { std: "docker" "start" "-a" "940aa81e4786202e302f066f71e84171f818c79cc472f00fed04e6f3b027d081", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]    --> lib.rs:194:13
[INFO] [stderr]     |
[INFO] [stderr] 194 |             try!(v.serialize(record, k, &mut ser))
[INFO] [stderr]     |             ^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(deprecated)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> lib.rs:94:44
[INFO] [stderr]    |
[INFO] [stderr] 94 | type RecordValues = Vec<(&'static str, Box<Serialize + Send>)>;
[INFO] [stderr]    |                                            ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 94 | type RecordValues = Vec<(&'static str, Box<dyn Serialize + Send>)>;
[INFO] [stderr]    |                                            +++
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> lib.rs:222:43
[INFO] [stderr]     |
[INFO] [stderr] 222 |     record_values: Vec<(&'static str, Box<Serialize + Send>)>,
[INFO] [stderr]     |                                           ^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]     = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]     |
[INFO] [stderr] 222 |     record_values: Vec<(&'static str, Box<dyn Serialize + Send>)>,
[INFO] [stderr]     |                                           +++
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> lib.rs:54:62
[INFO] [stderr]    |
[INFO] [stderr] 54 | ...                   .map(|&(k, ref v)| (k, v as &Serialize))
[INFO] [stderr]    |                                                    ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stderr]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 54 |                                 .map(|&(k, ref v)| (k, v as &dyn Serialize))
[INFO] [stderr]    |                                                              +++
[INFO] [stderr] 
[INFO] [stderr] warning: `slog-extra` (lib) generated 4 warnings (run `cargo fix --lib -p slog-extra` to apply 3 suggestions)
[INFO] [stderr] warning: `slog-extra` (lib test) generated 4 warnings (4 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running unittests lib.rs (/opt/rustwide/target/debug/deps/slog_extra-489def705d0d107a)
[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 slog_extra
[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" "940aa81e4786202e302f066f71e84171f818c79cc472f00fed04e6f3b027d081", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "940aa81e4786202e302f066f71e84171f818c79cc472f00fed04e6f3b027d081", kill_on_drop: false }`
[INFO] [stdout] 940aa81e4786202e302f066f71e84171f818c79cc472f00fed04e6f3b027d081
