[INFO] cloning repository https://github.com/ryosukeeeee/rust_rdbms_scratch
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ryosukeeeee/rust_rdbms_scratch" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryosukeeeee%2Frust_rdbms_scratch", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryosukeeeee%2Frust_rdbms_scratch'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 98e53fe3065b2dd8f2f595b369e2ac25e9c3237c
[INFO] testing ryosukeeeee/rust_rdbms_scratch against beta-2022-02-22 for beta-1.60-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fryosukeeeee%2Frust_rdbms_scratch" "/workspace/builds/worker-80/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-80/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ryosukeeeee/rust_rdbms_scratch on toolchain beta-2022-02-22
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-02-22" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ryosukeeeee/rust_rdbms_scratch
[INFO] finished tweaking git repo https://github.com/ryosukeeeee/rust_rdbms_scratch
[INFO] tweaked toml for git repo https://github.com/ryosukeeeee/rust_rdbms_scratch written to /workspace/builds/worker-80/source/Cargo.toml
[INFO] crate git repo https://github.com/ryosukeeeee/rust_rdbms_scratch already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2022-02-22" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-02-22" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 63dfe8f6a449c1a1bc3b841a58851ac79527f9a5c9a96b392b1ccd0985c07a40
[INFO] running `Command { std: "docker" "start" "-a" "63dfe8f6a449c1a1bc3b841a58851ac79527f9a5c9a96b392b1ccd0985c07a40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "63dfe8f6a449c1a1bc3b841a58851ac79527f9a5c9a96b392b1ccd0985c07a40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63dfe8f6a449c1a1bc3b841a58851ac79527f9a5c9a96b392b1ccd0985c07a40", kill_on_drop: false }`
[INFO] [stdout] 63dfe8f6a449c1a1bc3b841a58851ac79527f9a5c9a96b392b1ccd0985c07a40
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-02-22" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2e1292c037b018a66b4d72102e79ad5f2c05d02a8b06248935c480de578ca6cd
[INFO] running `Command { std: "docker" "start" "-a" "2e1292c037b018a66b4d72102e79ad5f2c05d02a8b06248935c480de578ca6cd", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.71
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling thiserror-impl v1.0.24
[INFO] [stderr]    Compiling thiserror v1.0.24
[INFO] [stderr]    Compiling rust_rdbms_practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `usage_count`
[INFO] [stdout]   --> src/buffer.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     usage_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `buffer`
[INFO] [stdout]   --> src/buffer.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     buffer: Rc<Buffer>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next_victim_id`
[INFO] [stdout]   --> src/buffer.rs:31:5
[INFO] [stdout]    |
[INFO] [stdout] 31 |     next_victim_id: BufferId,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `size`
[INFO] [stdout]   --> src/buffer.rs:35:8
[INFO] [stdout]    |
[INFO] [stdout] 35 |     fn size(&self) -> usize {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `evict`
[INFO] [stdout]   --> src/buffer.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 39 |     fn evict(&mut self) -> Option<BufferId> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `increment_id`
[INFO] [stdout]   --> src/buffer.rs:65:8
[INFO] [stdout]    |
[INFO] [stdout] 65 |     fn increment_id(&self, buffer_id: BufferId) -> BufferId {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `disk`
[INFO] [stdout]   --> src/buffer.rs:85:5
[INFO] [stdout]    |
[INFO] [stdout] 85 |     disk: DiskManager,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `pool`
[INFO] [stdout]   --> src/buffer.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     pool: BufferPool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `page_table`
[INFO] [stdout]   --> src/buffer.rs:87:5
[INFO] [stdout]    |
[INFO] [stdout] 87 |     page_table: HashMap<PageId, BufferId>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `fetch_page`
[INFO] [stdout]   --> src/buffer.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn fetch_page(&mut self, page_id: PageId) -> Result<Rc<Buffer>, Error> {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3m 17s
[INFO] running `Command { std: "docker" "inspect" "2e1292c037b018a66b4d72102e79ad5f2c05d02a8b06248935c480de578ca6cd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e1292c037b018a66b4d72102e79ad5f2c05d02a8b06248935c480de578ca6cd", kill_on_drop: false }`
[INFO] [stdout] 2e1292c037b018a66b4d72102e79ad5f2c05d02a8b06248935c480de578ca6cd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-02-22" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3b019db26544c3d84d9e7ffa62848fa916768b7773599970b0887bc419b0152d
[INFO] running `Command { std: "docker" "start" "-a" "3b019db26544c3d84d9e7ffa62848fa916768b7773599970b0887bc419b0152d", kill_on_drop: false }`
[INFO] [stdout] warning: field is never read: `usage_count`
[INFO] [stdout]   --> src/buffer.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     usage_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rust_rdbms_practice v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `buffer`
[INFO] [stdout]   --> src/buffer.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     buffer: Rc<Buffer>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next_victim_id`
[INFO] [stdout]   --> src/buffer.rs:31:5
[INFO] [stdout]    |
[INFO] [stdout] 31 |     next_victim_id: BufferId,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `size`
[INFO] [stdout]   --> src/buffer.rs:35:8
[INFO] [stdout]    |
[INFO] [stdout] 35 |     fn size(&self) -> usize {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `evict`
[INFO] [stdout]   --> src/buffer.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 39 |     fn evict(&mut self) -> Option<BufferId> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `increment_id`
[INFO] [stdout]   --> src/buffer.rs:65:8
[INFO] [stdout]    |
[INFO] [stdout] 65 |     fn increment_id(&self, buffer_id: BufferId) -> BufferId {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `disk`
[INFO] [stdout]   --> src/buffer.rs:85:5
[INFO] [stdout]    |
[INFO] [stdout] 85 |     disk: DiskManager,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `pool`
[INFO] [stdout]   --> src/buffer.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     pool: BufferPool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `page_table`
[INFO] [stdout]   --> src/buffer.rs:87:5
[INFO] [stdout]    |
[INFO] [stdout] 87 |     page_table: HashMap<PageId, BufferId>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `fetch_page`
[INFO] [stdout]   --> src/buffer.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn fetch_page(&mut self, page_id: PageId) -> Result<Rc<Buffer>, Error> {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `usage_count`
[INFO] [stdout]   --> src/buffer.rs:26:5
[INFO] [stdout]    |
[INFO] [stdout] 26 |     usage_count: u64,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `buffer`
[INFO] [stdout]   --> src/buffer.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 |     buffer: Rc<Buffer>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `next_victim_id`
[INFO] [stdout]   --> src/buffer.rs:31:5
[INFO] [stdout]    |
[INFO] [stdout] 31 |     next_victim_id: BufferId,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `size`
[INFO] [stdout]   --> src/buffer.rs:35:8
[INFO] [stdout]    |
[INFO] [stdout] 35 |     fn size(&self) -> usize {
[INFO] [stdout]    |        ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `evict`
[INFO] [stdout]   --> src/buffer.rs:39:8
[INFO] [stdout]    |
[INFO] [stdout] 39 |     fn evict(&mut self) -> Option<BufferId> {
[INFO] [stdout]    |        ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `increment_id`
[INFO] [stdout]   --> src/buffer.rs:65:8
[INFO] [stdout]    |
[INFO] [stdout] 65 |     fn increment_id(&self, buffer_id: BufferId) -> BufferId {
[INFO] [stdout]    |        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `disk`
[INFO] [stdout]   --> src/buffer.rs:85:5
[INFO] [stdout]    |
[INFO] [stdout] 85 |     disk: DiskManager,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `pool`
[INFO] [stdout]   --> src/buffer.rs:86:5
[INFO] [stdout]    |
[INFO] [stdout] 86 |     pool: BufferPool,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `page_table`
[INFO] [stdout]   --> src/buffer.rs:87:5
[INFO] [stdout]    |
[INFO] [stdout] 87 |     page_table: HashMap<PageId, BufferId>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `fetch_page`
[INFO] [stdout]   --> src/buffer.rs:91:8
[INFO] [stdout]    |
[INFO] [stdout] 91 |     fn fetch_page(&mut self, page_id: PageId) -> Result<Rc<Buffer>, Error> {
[INFO] [stdout]    |        ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.40s
[INFO] running `Command { std: "docker" "inspect" "3b019db26544c3d84d9e7ffa62848fa916768b7773599970b0887bc419b0152d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b019db26544c3d84d9e7ffa62848fa916768b7773599970b0887bc419b0152d", kill_on_drop: false }`
[INFO] [stdout] 3b019db26544c3d84d9e7ffa62848fa916768b7773599970b0887bc419b0152d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2022-02-22" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] ce0f32d6005b8bc34717ed46f018e9d4d0e58a42c291f0bb187229077f1616fe
[INFO] running `Command { std: "docker" "start" "-a" "ce0f32d6005b8bc34717ed46f018e9d4d0e58a42c291f0bb187229077f1616fe", kill_on_drop: false }`
[INFO] [stderr] warning: field is never read: `usage_count`
[INFO] [stderr]   --> src/buffer.rs:26:5
[INFO] [stderr]    |
[INFO] [stderr] 26 |     usage_count: u64,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `buffer`
[INFO] [stderr]   --> src/buffer.rs:27:5
[INFO] [stderr]    |
[INFO] [stderr] 27 |     buffer: Rc<Buffer>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `next_victim_id`
[INFO] [stderr]   --> src/buffer.rs:31:5
[INFO] [stderr]    |
[INFO] [stderr] 31 |     next_victim_id: BufferId,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `size`
[INFO] [stderr]   --> src/buffer.rs:35:8
[INFO] [stderr]    |
[INFO] [stderr] 35 |     fn size(&self) -> usize {
[INFO] [stderr]    |        ^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `evict`
[INFO] [stderr]   --> src/buffer.rs:39:8
[INFO] [stderr]    |
[INFO] [stderr] 39 |     fn evict(&mut self) -> Option<BufferId> {
[INFO] [stderr]    |        ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `increment_id`
[INFO] [stderr]   --> src/buffer.rs:65:8
[INFO] [stderr]    |
[INFO] [stderr] 65 |     fn increment_id(&self, buffer_id: BufferId) -> BufferId {
[INFO] [stderr]    |        ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `disk`
[INFO] [stderr]   --> src/buffer.rs:85:5
[INFO] [stderr]    |
[INFO] [stderr] 85 |     disk: DiskManager,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `pool`
[INFO] [stderr]   --> src/buffer.rs:86:5
[INFO] [stderr]    |
[INFO] [stderr] 86 |     pool: BufferPool,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field is never read: `page_table`
[INFO] [stderr]   --> src/buffer.rs:87:5
[INFO] [stderr]    |
[INFO] [stderr] 87 |     page_table: HashMap<PageId, BufferId>,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: associated function is never used: `fetch_page`
[INFO] [stderr]   --> src/buffer.rs:91:8
[INFO] [stderr]    |
[INFO] [stderr] 91 |     fn fetch_page(&mut self, page_id: PageId) -> Result<Rc<Buffer>, Error> {
[INFO] [stderr]    |        ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `rust_rdbms_practice` (lib) generated 10 warnings
[INFO] [stderr] warning: `rust_rdbms_practice` (lib test) generated 10 warnings (10 duplicates)
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/rust_rdbms_practice-2dfe1840aa6686e2)
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests rust_rdbms_practice
[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" "ce0f32d6005b8bc34717ed46f018e9d4d0e58a42c291f0bb187229077f1616fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce0f32d6005b8bc34717ed46f018e9d4d0e58a42c291f0bb187229077f1616fe", kill_on_drop: false }`
[INFO] [stdout] ce0f32d6005b8bc34717ed46f018e9d4d0e58a42c291f0bb187229077f1616fe