[INFO] fetching crate synstructure_test_traits 0.1.0...
[INFO] testing synstructure_test_traits-0.1.0 against 1.60.0 for beta-1.61-1
[INFO] extracting crate synstructure_test_traits 0.1.0 into /workspace/builds/worker-17/source
[INFO] validating manifest of crates.io crate synstructure_test_traits 0.1.0 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate synstructure_test_traits 0.1.0
[INFO] finished tweaking crates.io crate synstructure_test_traits 0.1.0
[INFO] tweaked toml for crates.io crate synstructure_test_traits 0.1.0 written to /workspace/builds/worker-17/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a06c84c87a15dcd53f7185b34d1f6c5098937f3676576c63240d3a6db1005c3c
[INFO] running `Command { std: "docker" "start" "-a" "a06c84c87a15dcd53f7185b34d1f6c5098937f3676576c63240d3a6db1005c3c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a06c84c87a15dcd53f7185b34d1f6c5098937f3676576c63240d3a6db1005c3c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a06c84c87a15dcd53f7185b34d1f6c5098937f3676576c63240d3a6db1005c3c", kill_on_drop: false }`
[INFO] [stdout] a06c84c87a15dcd53f7185b34d1f6c5098937f3676576c63240d3a6db1005c3c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ca27653142a5d09e087c3bad1ca013352382996183ca494ab006c32928d0524e
[INFO] running `Command { std: "docker" "start" "-a" "ca27653142a5d09e087c3bad1ca013352382996183ca494ab006c32928d0524e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling synstructure_test_traits v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:38
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut dyn FnMut(&WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut FnMut(&dyn WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:39
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut dyn FnMut(&WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:46
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut FnMut(&dyn WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.89s
[INFO] running `Command { std: "docker" "inspect" "ca27653142a5d09e087c3bad1ca013352382996183ca494ab006c32928d0524e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca27653142a5d09e087c3bad1ca013352382996183ca494ab006c32928d0524e", kill_on_drop: false }`
[INFO] [stdout] ca27653142a5d09e087c3bad1ca013352382996183ca494ab006c32928d0524e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ca19d15defb0e157d310b0831f7f895ea1fe6e91561d107ec279acffb4c42c66
[INFO] running `Command { std: "docker" "start" "-a" "ca19d15defb0e157d310b0831f7f895ea1fe6e91561d107ec279acffb4c42c66", kill_on_drop: false }`
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:38
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut dyn FnMut(&WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut FnMut(&dyn WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:39
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut dyn FnMut(&WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling synstructure_test_traits v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:46
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut FnMut(&dyn WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:38
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` on by default
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut dyn FnMut(&WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> lib.rs:7:45
[INFO] [stdout]   |
[INFO] [stdout] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stdout] 7 +     fn walk_fields(&self, walk: &mut FnMut(&dyn WalkFields));
[INFO] [stdout]   | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:39
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut dyn FnMut(&WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> lib.rs:10:46
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stdout] 10 +     fn walk_fields(&self, _walk: &mut FnMut(&dyn WalkFields)) {}
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "ca19d15defb0e157d310b0831f7f895ea1fe6e91561d107ec279acffb4c42c66", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca19d15defb0e157d310b0831f7f895ea1fe6e91561d107ec279acffb4c42c66", kill_on_drop: false }`
[INFO] [stdout] ca19d15defb0e157d310b0831f7f895ea1fe6e91561d107ec279acffb4c42c66
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] cec8c5596854f100b0dd672a7a0b196100bd6fe64c42ba6acc83e1a7d95e6a1a
[INFO] running `Command { std: "docker" "start" "-a" "cec8c5596854f100b0dd672a7a0b196100bd6fe64c42ba6acc83e1a7d95e6a1a", kill_on_drop: false }`
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]  --> lib.rs:7:38
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stderr]   |                                      ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(bare_trait_objects)]` on by default
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: use `dyn`
[INFO] [stderr]   |
[INFO] [stderr] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stderr] 7 +     fn walk_fields(&self, walk: &mut dyn FnMut(&WalkFields));
[INFO] [stderr]   | 
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]  --> lib.rs:7:45
[INFO] [stderr]   |
[INFO] [stderr] 7 |     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: use `dyn`
[INFO] [stderr]   |
[INFO] [stderr] 7 -     fn walk_fields(&self, walk: &mut FnMut(&WalkFields));
[INFO] [stderr] 7 +     fn walk_fields(&self, walk: &mut FnMut(&dyn WalkFields));
[INFO] [stderr]   | 
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> lib.rs:10:39
[INFO] [stderr]    |
[INFO] [stderr] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stderr] 10 +     fn walk_fields(&self, _walk: &mut dyn FnMut(&WalkFields)) {}
[INFO] [stderr]    | 
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> lib.rs:10:46
[INFO] [stderr]    |
[INFO] [stderr] 10 |     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[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/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stderr] help: use `dyn`
[INFO] [stderr]    |
[INFO] [stderr] 10 -     fn walk_fields(&self, _walk: &mut FnMut(&WalkFields)) {}
[INFO] [stderr] 10 +     fn walk_fields(&self, _walk: &mut FnMut(&dyn WalkFields)) {}
[INFO] [stderr]    | 
[INFO] [stderr] 
[INFO] [stderr] warning: `synstructure_test_traits` (lib) generated 4 warnings
[INFO] [stderr] warning: `synstructure_test_traits` (lib test) generated 4 warnings (4 duplicates)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.00s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/synstructure_test_traits-bf7c06aa5e9aef2c)
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests synstructure_test_traits
[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] running `Command { std: "docker" "inspect" "cec8c5596854f100b0dd672a7a0b196100bd6fe64c42ba6acc83e1a7d95e6a1a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cec8c5596854f100b0dd672a7a0b196100bd6fe64c42ba6acc83e1a7d95e6a1a", kill_on_drop: false }`
[INFO] [stdout] cec8c5596854f100b0dd672a7a0b196100bd6fe64c42ba6acc83e1a7d95e6a1a