[INFO] cloning repository https://github.com/iuhmirza/kv-db
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/iuhmirza/kv-db" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiuhmirza%2Fkv-db", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiuhmirza%2Fkv-db'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fadadd2dd59e560a7d06bdbddcfeee49d462eb8e
[INFO] testing iuhmirza/kv-db against beta-2026-04-21 for beta-1.96-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fiuhmirza%2Fkv-db" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/iuhmirza/kv-db
[INFO] finished tweaking git repo https://github.com/iuhmirza/kv-db
[INFO] tweaked toml for git repo https://github.com/iuhmirza/kv-db written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/iuhmirza/kv-db 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] crate git repo https://github.com/iuhmirza/kv-db 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" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 8ff63c6832f44e2d7cd90626aa802519cf89e5a9a3312961988113db0ddbf537
[INFO] running `Command { std: "docker" "start" "-a" "8ff63c6832f44e2d7cd90626aa802519cf89e5a9a3312961988113db0ddbf537", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8ff63c6832f44e2d7cd90626aa802519cf89e5a9a3312961988113db0ddbf537", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ff63c6832f44e2d7cd90626aa802519cf89e5a9a3312961988113db0ddbf537", kill_on_drop: false }`
[INFO] [stdout] 8ff63c6832f44e2d7cd90626aa802519cf89e5a9a3312961988113db0ddbf537
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 26633f853aa1a0932e7b7c515bd6261ee6fb8df46dd4078486c38fe130a5b78e
[INFO] running `Command { std: "docker" "start" "-a" "26633f853aa1a0932e7b7c515bd6261ee6fb8df46dd4078486c38fe130a5b78e", kill_on_drop: false }`
[INFO] [stderr]    Compiling kv-db v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:21:26
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                          ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]   --> src/lock.rs:21:31
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 |             Request::Delete(key) => match map.write() {
[INFO] [stdout]    |                             ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:23:17
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 tx.send(value);
[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)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 let _ = tx.send(value);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:45:17
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 sender.send(Command::Get(key, tx));
[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] 45 |                 let _ = sender.send(Command::Get(key, tx));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:53:17
[INFO] [stdout]    |
[INFO] [stdout] 53 |                 sender.send(Command::Put(key, value));
[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 _ = sender.send(Command::Put(key, value));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:56:17
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 sender.send(Command::Delete(key));
[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] 56 |                 let _ = sender.send(Command::Delete(key));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.50s
[INFO] running `Command { std: "docker" "inspect" "26633f853aa1a0932e7b7c515bd6261ee6fb8df46dd4078486c38fe130a5b78e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "26633f853aa1a0932e7b7c515bd6261ee6fb8df46dd4078486c38fe130a5b78e", kill_on_drop: false }`
[INFO] [stdout] 26633f853aa1a0932e7b7c515bd6261ee6fb8df46dd4078486c38fe130a5b78e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] f528f9ef9ca4ca4630529c9d17eaca739da812f57ef9f9af7bdbe8f532792145
[INFO] running `Command { std: "docker" "start" "-a" "f528f9ef9ca4ca4630529c9d17eaca739da812f57ef9f9af7bdbe8f532792145", kill_on_drop: false }`
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:21:26
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                          ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]   --> src/lock.rs:21:31
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 |             Request::Delete(key) => match map.write() {
[INFO] [stdout]    |                             ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:23:17
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 tx.send(value);
[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)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 let _ = tx.send(value);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:45:17
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 sender.send(Command::Get(key, tx));
[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] 45 |                 let _ = sender.send(Command::Get(key, tx));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:53:17
[INFO] [stdout]    |
[INFO] [stdout] 53 |                 sender.send(Command::Put(key, value));
[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 _ = sender.send(Command::Put(key, value));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:56:17
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 sender.send(Command::Delete(key));
[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] 56 |                 let _ = sender.send(Command::Delete(key));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling kv-db v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ----^^^
[INFO] [stdout]    |                    |
[INFO] [stdout]    |                    help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:21:26
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                          ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `value`
[INFO] [stdout]   --> src/lock.rs:21:31
[INFO] [stdout]    |
[INFO] [stdout] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stdout]    |                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:22:20
[INFO] [stdout]    |
[INFO] [stdout] 22 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `key`
[INFO] [stdout]   --> src/lock.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 |             Request::Delete(key) => match map.write() {
[INFO] [stdout]    |                             ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `map`
[INFO] [stdout]   --> src/lock.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |                 Ok(mut map) => {
[INFO] [stdout]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:23:17
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 tx.send(value);
[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)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 23 |                 let _ = tx.send(value);
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:45:17
[INFO] [stdout]    |
[INFO] [stdout] 45 |                 sender.send(Command::Get(key, tx));
[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] 45 |                 let _ = sender.send(Command::Get(key, tx));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:53:17
[INFO] [stdout]    |
[INFO] [stdout] 53 |                 sender.send(Command::Put(key, value));
[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 _ = sender.send(Command::Put(key, value));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/mp.rs:56:17
[INFO] [stdout]    |
[INFO] [stdout] 56 |                 sender.send(Command::Delete(key));
[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] 56 |                 let _ = sender.send(Command::Delete(key));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.50s
[INFO] running `Command { std: "docker" "inspect" "f528f9ef9ca4ca4630529c9d17eaca739da812f57ef9f9af7bdbe8f532792145", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f528f9ef9ca4ca4630529c9d17eaca739da812f57ef9f9af7bdbe8f532792145", kill_on_drop: false }`
[INFO] [stdout] f528f9ef9ca4ca4630529c9d17eaca739da812f57ef9f9af7bdbe8f532792145
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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] 5b349f3e10c9a30742299cba5df7f2b33089a7f4f3eb615f14740b79dcd11742
[INFO] running `Command { std: "docker" "start" "-a" "5b349f3e10c9a30742299cba5df7f2b33089a7f4f3eb615f14740b79dcd11742", kill_on_drop: false }`
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/lock.rs:22:20
[INFO] [stderr]    |
[INFO] [stderr] 22 |                 Ok(mut map) => {
[INFO] [stderr]    |                    ----^^^
[INFO] [stderr]    |                    |
[INFO] [stderr]    |                    help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/lock.rs:29:20
[INFO] [stderr]    |
[INFO] [stderr] 29 |                 Ok(mut map) => {
[INFO] [stderr]    |                    ----^^^
[INFO] [stderr]    |                    |
[INFO] [stderr]    |                    help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `key`
[INFO] [stderr]   --> src/lock.rs:21:26
[INFO] [stderr]    |
[INFO] [stderr] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stderr]    |                          ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `value`
[INFO] [stderr]   --> src/lock.rs:21:31
[INFO] [stderr]    |
[INFO] [stderr] 21 |             Request::Put(key, value) => match map.write() {
[INFO] [stderr]    |                               ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `map`
[INFO] [stderr]   --> src/lock.rs:22:20
[INFO] [stderr]    |
[INFO] [stderr] 22 |                 Ok(mut map) => {
[INFO] [stderr]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `key`
[INFO] [stderr]   --> src/lock.rs:28:29
[INFO] [stderr]    |
[INFO] [stderr] 28 |             Request::Delete(key) => match map.write() {
[INFO] [stderr]    |                             ^^^ help: if this is intentional, prefix it with an underscore: `_key`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `map`
[INFO] [stderr]   --> src/lock.rs:29:20
[INFO] [stderr]    |
[INFO] [stderr] 29 |                 Ok(mut map) => {
[INFO] [stderr]    |                    ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_map`
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/mp.rs:23:17
[INFO] [stderr]    |
[INFO] [stderr] 23 |                 tx.send(value);
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 23 |                 let _ = tx.send(value);
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/mp.rs:45:17
[INFO] [stderr]    |
[INFO] [stderr] 45 |                 sender.send(Command::Get(key, tx));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 45 |                 let _ = sender.send(Command::Get(key, tx));
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/mp.rs:53:17
[INFO] [stderr]    |
[INFO] [stderr] 53 |                 sender.send(Command::Put(key, value));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 53 |                 let _ = sender.send(Command::Put(key, value));
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/mp.rs:56:17
[INFO] [stderr]    |
[INFO] [stderr] 56 |                 sender.send(Command::Delete(key));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]    |
[INFO] [stderr] 56 |                 let _ = sender.send(Command::Delete(key));
[INFO] [stderr]    |                 +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: `kv-db` (lib) generated 11 warnings (run `cargo fix --lib -p kv-db` to apply 7 suggestions)
[INFO] [stderr] warning: `kv-db` (lib test) generated 11 warnings (11 duplicates)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.04s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/kv_db-d061cea5930d8d46)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/client.rs (/opt/rustwide/target/debug/deps/client-452a7dd07bb33ef4)
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/lock.rs (/opt/rustwide/target/debug/deps/lock-bf6904e6874a14d4)
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/mp.rs (/opt/rustwide/target/debug/deps/mp-53e937592e7cc639)
[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 kv_db
[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" "5b349f3e10c9a30742299cba5df7f2b33089a7f4f3eb615f14740b79dcd11742", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b349f3e10c9a30742299cba5df7f2b33089a7f4f3eb615f14740b79dcd11742", kill_on_drop: false }`
[INFO] [stdout] 5b349f3e10c9a30742299cba5df7f2b33089a7f4f3eb615f14740b79dcd11742
