[INFO] fetching crate aught_common 0.1.0...
[INFO] checking aught_common-0.1.0 against master#80399064afa4a2cd153f30d02c25f7ea0383ed65 for opaque-soundness-fix
[INFO] extracting crate aught_common 0.1.0 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate aught_common 0.1.0 on toolchain 80399064afa4a2cd153f30d02c25f7ea0383ed65
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+80399064afa4a2cd153f30d02c25f7ea0383ed65" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate aught_common 0.1.0
[INFO] finished tweaking crates.io crate aught_common 0.1.0
[INFO] tweaked toml for crates.io crate aught_common 0.1.0 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+80399064afa4a2cd153f30d02c25f7ea0383ed65" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+80399064afa4a2cd153f30d02c25f7ea0383ed65" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+80399064afa4a2cd153f30d02c25f7ea0383ed65" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5f8d3472713bd731a1c58ae0f275691bb8905da2980aa5422ef07a84fcf2296d
[INFO] running `Command { std: "docker" "start" "-a" "5f8d3472713bd731a1c58ae0f275691bb8905da2980aa5422ef07a84fcf2296d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5f8d3472713bd731a1c58ae0f275691bb8905da2980aa5422ef07a84fcf2296d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f8d3472713bd731a1c58ae0f275691bb8905da2980aa5422ef07a84fcf2296d", kill_on_drop: false }`
[INFO] [stdout] 5f8d3472713bd731a1c58ae0f275691bb8905da2980aa5422ef07a84fcf2296d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+80399064afa4a2cd153f30d02c25f7ea0383ed65" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fe0c45386d33ace0ce939e1c94f2f0e12490d7f334aab5c36590fe7e7036475e
[INFO] running `Command { std: "docker" "start" "-a" "fe0c45386d33ace0ce939e1c94f2f0e12490d7f334aab5c36590fe7e7036475e", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition
[INFO] [stderr]    Compiling serde v1.0.197
[INFO] [stderr]     Checking serde_json v1.0.114
[INFO] [stderr]     Checking aught_common v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/error.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/sender.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/reciever.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]   --> src/command.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     use serde_json;
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/lib.rs:2:1
[INFO] [stdout]    |
[INFO] [stdout] 2  | extern crate serde_json;
[INFO] [stdout]    | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/error.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/sender.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/sender.rs:7:16
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut Write,
[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]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut dyn Write,
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/error.rs:26:32
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&Error> {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/sender.rs:11:27
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut Write) -> Sender {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut dyn Write) -> Sender {
[INFO] [stdout]    |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/sender.rs:7:16
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut Write,
[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]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut dyn Write,
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/error.rs:26:32
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&Error> {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/sender.rs:11:27
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut Write) -> Sender {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut dyn Write) -> Sender {
[INFO] [stdout]    |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.71s
[INFO] running `Command { std: "docker" "inspect" "fe0c45386d33ace0ce939e1c94f2f0e12490d7f334aab5c36590fe7e7036475e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fe0c45386d33ace0ce939e1c94f2f0e12490d7f334aab5c36590fe7e7036475e", kill_on_drop: false }`
[INFO] [stdout] fe0c45386d33ace0ce939e1c94f2f0e12490d7f334aab5c36590fe7e7036475e
[INFO] checking aught_common-0.1.0 against master#09bc67b9158392361780e779d32997f14cc75c39 for opaque-soundness-fix
[INFO] extracting crate aught_common 0.1.0 into /workspace/builds/worker-7-tc2/source
[INFO] validating manifest of crates.io crate aught_common 0.1.0 on toolchain 09bc67b9158392361780e779d32997f14cc75c39
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+09bc67b9158392361780e779d32997f14cc75c39" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate aught_common 0.1.0
[INFO] finished tweaking crates.io crate aught_common 0.1.0
[INFO] tweaked toml for crates.io crate aught_common 0.1.0 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+09bc67b9158392361780e779d32997f14cc75c39" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+09bc67b9158392361780e779d32997f14cc75c39" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+09bc67b9158392361780e779d32997f14cc75c39" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ce0a17688c15398101d6d9ee7493552ea935a507ae3353ed2cd7541c938c45a1
[INFO] running `Command { std: "docker" "start" "-a" "ce0a17688c15398101d6d9ee7493552ea935a507ae3353ed2cd7541c938c45a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ce0a17688c15398101d6d9ee7493552ea935a507ae3353ed2cd7541c938c45a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce0a17688c15398101d6d9ee7493552ea935a507ae3353ed2cd7541c938c45a1", kill_on_drop: false }`
[INFO] [stdout] ce0a17688c15398101d6d9ee7493552ea935a507ae3353ed2cd7541c938c45a1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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=forbid" "-e" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+09bc67b9158392361780e779d32997f14cc75c39" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7014b89fe3bf1ebf30aa870a2a0c9e40b2e8d523b7f09ab83f2cd32b1130e5b0
[INFO] running `Command { std: "docker" "start" "-a" "7014b89fe3bf1ebf30aa870a2a0c9e40b2e8d523b7f09ab83f2cd32b1130e5b0", kill_on_drop: false }`
[INFO] [stderr] warning: no edition set: defaulting to the 2015 edition
[INFO] [stderr]    Compiling serde v1.0.197
[INFO] [stderr]     Checking serde_json v1.0.114
[INFO] [stderr]     Checking aught_common v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/error.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/sender.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/reciever.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]   --> src/command.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     use serde_json;
[INFO] [stdout]    |         ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/lib.rs:2:1
[INFO] [stdout]    |
[INFO] [stdout] 2  | extern crate serde_json;
[INFO] [stdout]    | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/error.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `serde_json` is imported redundantly
[INFO] [stdout]  --> src/sender.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json;
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]  ::: src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | extern crate serde_json;
[INFO] [stdout]   | ------------------------ the item `serde_json` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/sender.rs:7:16
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut Write,
[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]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut dyn Write,
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/error.rs:26:32
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&Error> {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/sender.rs:11:27
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut Write) -> Sender {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut dyn Write) -> Sender {
[INFO] [stdout]    |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> src/sender.rs:7:16
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut Write,
[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]   = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 7 |     w: &'a mut dyn Write,
[INFO] [stdout]   |                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/error.rs:26:32
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&Error> {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 26 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]    |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/sender.rs:11:27
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut Write) -> Sender {
[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: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 11 |     pub fn new(w: &'a mut dyn Write) -> Sender {
[INFO] [stdout]    |                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 6 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.87s
[INFO] running `Command { std: "docker" "inspect" "7014b89fe3bf1ebf30aa870a2a0c9e40b2e8d523b7f09ab83f2cd32b1130e5b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7014b89fe3bf1ebf30aa870a2a0c9e40b2e8d523b7f09ab83f2cd32b1130e5b0", kill_on_drop: false }`
[INFO] [stdout] 7014b89fe3bf1ebf30aa870a2a0c9e40b2e8d523b7f09ab83f2cd32b1130e5b0
