[INFO] cloning repository https://github.com/Etc3tera/RustFSExample
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Etc3tera/RustFSExample" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEtc3tera%2FRustFSExample", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEtc3tera%2FRustFSExample'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 819834b85797802f3788cd6a24028f7d8ca252a0
[INFO] checking Etc3tera/RustFSExample/819834b85797802f3788cd6a24028f7d8ca252a0 against try#4d98531622e1718ae0bc3c7a1ab9cd8938428452+rustflags=-Dtail_expr_drop_order for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEtc3tera%2FRustFSExample" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Etc3tera/RustFSExample on toolchain 4d98531622e1718ae0bc3c7a1ab9cd8938428452
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Etc3tera/RustFSExample
[INFO] finished tweaking git repo https://github.com/Etc3tera/RustFSExample
[INFO] tweaked toml for git repo https://github.com/Etc3tera/RustFSExample written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Etc3tera/RustFSExample already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 392e941733a9442b25ddf20d87026d6e772461c984b7bccf9dfaa648f475af54
[INFO] running `Command { std: "docker" "start" "-a" "392e941733a9442b25ddf20d87026d6e772461c984b7bccf9dfaa648f475af54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "392e941733a9442b25ddf20d87026d6e772461c984b7bccf9dfaa648f475af54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "392e941733a9442b25ddf20d87026d6e772461c984b7bccf9dfaa648f475af54", kill_on_drop: false }`
[INFO] [stdout] 392e941733a9442b25ddf20d87026d6e772461c984b7bccf9dfaa648f475af54
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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 -Dtail_expr_drop_order" "-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+4d98531622e1718ae0bc3c7a1ab9cd8938428452" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fb45504da1098df1913bc1eb9de5fe0068d9f00fa039fdfc1a4108f9d1227d0a
[INFO] running `Command { std: "docker" "start" "-a" "fb45504da1098df1913bc1eb9de5fe0068d9f00fa039fdfc1a4108f9d1227d0a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.3
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling serde v1.0.100
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]    Compiling autocfg v0.1.6
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]    Compiling bincode v1.1.4
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.100
[INFO] [stderr]     Checking serde_json v1.0.40
[INFO] [stderr]     Checking rust_fs_io v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fp.write_all(b"1");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let _ = fp.write_all(b"1");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fp.write_all(b"2");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let _ = fp.write_all(b"2");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fp.write_all(b"3");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let _ = fp.write_all(b"3");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:22:5
[INFO] [stdout]    |
[INFO] [stdout] 22 |     fp.seek(SeekFrom::Start(0));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let _ = fp.seek(SeekFrom::Start(0));
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fp.write_all(b"4");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let _ = fp.write_all(b"4");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 |     fp.write_all(b"5");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let _ = fp.write_all(b"5");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `serde_json::Result`
[INFO] [stdout]  --> src/serialize_text.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json::Result;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `serde_json::Result`
[INFO] [stdout]  --> src/serialize_text.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use serde_json::Result;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::SeekFrom`
[INFO] [stdout]  --> src/serialize_binary.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::SeekFrom;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 15 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     fp.write_all(b"1");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let _ = fp.write_all(b"1");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:17:5
[INFO] [stdout]    |
[INFO] [stdout] 17 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 17 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::SeekFrom`
[INFO] [stdout]  --> src/serialize_binary.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::io::SeekFrom;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fp.write_all(b"2");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 18 |     let _ = fp.write_all(b"2");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:20:5
[INFO] [stdout]    |
[INFO] [stdout] 20 |     fp.write_all(b"3");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let _ = fp.write_all(b"3");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
[INFO] [stdout]  --> src/serialize_text.rs:6:28
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(Debug, Serialize, Deserialize)]
[INFO] [stdout]   |                            ^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this changes meaning in Rust 2024
[INFO] [stdout]   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
[INFO] [stdout]   = note: requested on the command line with `-D tail-expr-drop-order`
[INFO] [stdout]   = note: this error originates in the macro `try` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
[INFO] [stdout]  --> src/serialize_text.rs:6:28
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(Debug, Serialize, Deserialize)]
[INFO] [stdout]   |                            ^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this changes meaning in Rust 2024
[INFO] [stdout]   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
[INFO] [stdout]   = note: requested on the command line with `-D tail-expr-drop-order`
[INFO] [stdout]   = note: this error originates in the macro `try` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:21:5
[INFO] [stdout]    |
[INFO] [stdout] 21 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 21 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:22:5
[INFO] [stdout]    |
[INFO] [stdout] 22 |     fp.seek(SeekFrom::Start(0));
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 22 |     let _ = fp.seek(SeekFrom::Start(0));
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:23:5
[INFO] [stdout]    |
[INFO] [stdout] 23 |     fp.write_all(b"4");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |     let _ = fp.write_all(b"4");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 24 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 |     fp.write_all(b"5");
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 25 |     let _ = fp.write_all(b"5");
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/example.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let _ = stdin.lock().read_line(&mut line);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_text.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |         fp.write_all(json.as_bytes());
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 44 |         let _ = fp.write_all(json.as_bytes());
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_text.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     fp.read_to_string(&mut buffer);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let _ = fp.read_to_string(&mut buffer);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_fs_io` (bin "serialize_text" test) due to 2 previous errors; 3 warnings emitted
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_text.rs:44:9
[INFO] [stdout]    |
[INFO] [stdout] 44 |         fp.write_all(json.as_bytes());
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 44 |         let _ = fp.write_all(json.as_bytes());
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_text.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     fp.read_to_string(&mut buffer);
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let _ = fp.read_to_string(&mut buffer);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
[INFO] [stdout]  --> src/serialize_binary.rs:6:28
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(Debug, Serialize, Deserialize)]
[INFO] [stdout]   |                            ^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this changes meaning in Rust 2024
[INFO] [stdout]   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
[INFO] [stdout]   = note: requested on the command line with `-D tail-expr-drop-order`
[INFO] [stdout]   = note: this error originates in the macro `try` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_binary.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |         fp.write_all(&bin);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 47 |         let _ = fp.write_all(&bin);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: these values and local bindings have significant drop implementation that will have a different drop order from that of Edition 2021
[INFO] [stdout]  --> src/serialize_binary.rs:6:28
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(Debug, Serialize, Deserialize)]
[INFO] [stdout]   |                            ^^^^^^^^^^^ these values have significant drop implementation and will observe changes in drop order under Edition 2024
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this changes meaning in Rust 2024
[INFO] [stdout]   = note: for more information, see issue #123739 <https://github.com/rust-lang/rust/issues/123739>
[INFO] [stdout]   = note: requested on the command line with `-D tail-expr-drop-order`
[INFO] [stdout]   = note: this error originates in the macro `try` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_fs_io` (bin "serialize_text") due to 2 previous errors; 3 warnings emitted
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/serialize_binary.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |         fp.write_all(&bin);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 47 |         let _ = fp.write_all(&bin);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_fs_io` (bin "serialize_binary" test) due to 2 previous errors; 2 warnings emitted
[INFO] [stdout] error: aborting due to 1 previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_fs_io` (bin "serialize_binary") due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "fb45504da1098df1913bc1eb9de5fe0068d9f00fa039fdfc1a4108f9d1227d0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb45504da1098df1913bc1eb9de5fe0068d9f00fa039fdfc1a4108f9d1227d0a", kill_on_drop: false }`
[INFO] [stdout] fb45504da1098df1913bc1eb9de5fe0068d9f00fa039fdfc1a4108f9d1227d0a