[INFO] updating cached repository csherratt/BillBe [INFO] running `"git" "fetch" "--all"` [INFO] [stdout] Fetching origin [INFO] [stderr] From git://github.com/csherratt/BillBe [INFO] [stderr] * branch HEAD -> FETCH_HEAD [INFO] running `"git" "clone" "work/cache/sources/gh/csherratt/BillBe" "work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe"` [INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe'... [INFO] [stderr] done. [INFO] running `"git" "clone" "work/cache/sources/gh/csherratt/BillBe" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/csherratt/BillBe"` [INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/csherratt/BillBe'... [INFO] [stderr] done. [INFO] running `"git" "rev-parse" "HEAD"` [INFO] [stdout] 1e0ce967ca6e5d568a343bf7c76d0dedafc96de7 [INFO] sha for GitHub repo csherratt/BillBe: 1e0ce967ca6e5d568a343bf7c76d0dedafc96de7 [INFO] validating manifest of csherratt/BillBe on toolchain 1.37.0 [INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"` [INFO] validating manifest of csherratt/BillBe on toolchain beta-2019-08-13 [INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"` [INFO] started frobbing csherratt/BillBe [INFO] finished frobbing csherratt/BillBe [INFO] frobbed toml for csherratt/BillBe written to work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe/Cargo.toml [INFO] started frobbing csherratt/BillBe [INFO] finished frobbing csherratt/BillBe [INFO] frobbed toml for csherratt/BillBe written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/csherratt/BillBe/Cargo.toml [INFO] crate csherratt/BillBe already has a lockfile, it will not be regenerated [INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"` [INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"` [INFO] testing csherratt/BillBe against 1.37.0 for beta-1.38-1 [INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+1.37.0" "build" "--frozen"` [INFO] [stdout] 80ea93cd1dc416294f6d0217ce23779811ba43adc61be78462a236959b9ba94a [INFO] running `"docker" "start" "-a" "80ea93cd1dc416294f6d0217ce23779811ba43adc61be78462a236959b9ba94a"` [INFO] [stderr] Compiling zero v0.1.2 [INFO] [stderr] Compiling atty v0.2.2 [INFO] [stderr] Compiling mustache v0.8.0 [INFO] [stderr] Compiling serde_json v1.0.2 [INFO] [stderr] Compiling textwrap v0.6.0 [INFO] [stderr] Compiling hyper v0.10.12 [INFO] [stderr] Compiling serde_derive v1.0.9 [INFO] [stderr] Compiling xmas-elf v0.5.0 (https://github.com/talyxian/xmas-elf.git#1757ed69) [INFO] [stderr] Compiling clap v2.25.0 [INFO] [stderr] Compiling nickel v0.10.0 [INFO] [stderr] Compiling billbe v0.1.0 (/opt/crater/workdir) [INFO] [stderr] warning: unused `#[macro_use]` import [INFO] [stderr] --> src/main.rs:4:1 [INFO] [stderr] | [INFO] [stderr] 4 | #[macro_use] [INFO] [stderr] | ^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_imports)] on by default [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/rtc.rs:91:28 [INFO] [stderr] | [INFO] [stderr] 91 | (DATA_PORT, 0xe...0xff) => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] | [INFO] [stderr] = note: #[warn(ellipsis_inclusive_range_patterns)] on by default [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/rtc.rs:125:28 [INFO] [stderr] | [INFO] [stderr] 125 | (DATA_PORT, 0xe...0xff) => Ok(()), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: unused imports: `Arc`, `Mutex` [INFO] [stderr] --> src/main.rs:17:17 [INFO] [stderr] | [INFO] [stderr] 17 | use std::sync::{Arc, Mutex}; [INFO] [stderr] | ^^^ ^^^^^ [INFO] [stderr] [INFO] [stderr] warning: unused imports: `HttpRouter`, `Nickel` [INFO] [stderr] --> src/main.rs:22:14 [INFO] [stderr] | [INFO] [stderr] 22 | use nickel::{Nickel, HttpRouter}; [INFO] [stderr] | ^^^^^^ ^^^^^^^^^^ [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:244:26 [INFO] [stderr] | [INFO] [stderr] 244 | rtc::ADDR_LOW...rtc::ADDR_HIGH => self.rtc.read(addr, data), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:245:23 [INFO] [stderr] | [INFO] [stderr] 245 | 0x800_0000...0x880_0000 => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:290:26 [INFO] [stderr] | [INFO] [stderr] 290 | rtc::ADDR_LOW...rtc::ADDR_HIGH => self.rtc.write(addr, data), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:291:23 [INFO] [stderr] | [INFO] [stderr] 291 | 0x800_0000...0x880_0000 => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: unreachable expression [INFO] [stderr] --> src/hobbit/mmu.rs:193:17 [INFO] [stderr] | [INFO] [stderr] 193 | / return return Err(Error::BusFault { [INFO] [stderr] 194 | | address: addr, [INFO] [stderr] 195 | | mode: Mode::Read, [INFO] [stderr] 196 | | description: BusDescription::PageTableIsNotBacked, [INFO] [stderr] 197 | | }); [INFO] [stderr] | |____________________________________^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unreachable_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused import: `Write` [INFO] [stderr] --> src/main.rs:16:22 [INFO] [stderr] | [INFO] [stderr] 16 | use std::fmt::{self, Write}; [INFO] [stderr] | ^^^^^ [INFO] [stderr] [INFO] [stderr] warning: unused variable: `len` [INFO] [stderr] --> src/hobbit/mod.rs:746:13 [INFO] [stderr] | [INFO] [stderr] 746 | let len = self.pc.0 - self.instruction_pc.0; [INFO] [stderr] | ^^^ help: consider prefixing with an underscore: `_len` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_variables)] on by default [INFO] [stderr] [INFO] [stderr] warning: function is never used: `send_index` [INFO] [stderr] --> src/main.rs:445:1 [INFO] [stderr] | [INFO] [stderr] 445 | / fn send_index<'a, D>(_: &mut nickel::Request, [INFO] [stderr] 446 | | res: nickel::Response<'a, D>) [INFO] [stderr] 447 | | -> nickel::MiddlewareResult<'a, D> { [INFO] [stderr] 448 | | let index = std::path::Path::new("web/index.html"); [INFO] [stderr] 449 | | res.send_file(index) [INFO] [stderr] 450 | | } [INFO] [stderr] | |_^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(dead_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: the `mode:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:724:25 [INFO] [stderr] | [INFO] [stderr] 724 | mode: mode, [INFO] [stderr] | -----^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] | [INFO] [stderr] = note: #[warn(non_shorthand_field_patterns)] on by default [INFO] [stderr] [INFO] [stderr] warning: the `description:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:725:25 [INFO] [stderr] | [INFO] [stderr] 725 | description: description, [INFO] [stderr] | ------------^^^^^^^^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/hobbit/mod.rs:750:9 [INFO] [stderr] | [INFO] [stderr] 750 | self.explain(instruction, memory, symbols); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_must_use)] on by default [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: the `mode:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:817:24 [INFO] [stderr] | [INFO] [stderr] 817 | mode: mode, [INFO] [stderr] | -----^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] warning: the `description:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:818:24 [INFO] [stderr] | [INFO] [stderr] 818 | description: description, [INFO] [stderr] | ------------^^^^^^^^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 48.32s [INFO] running `"docker" "inspect" "80ea93cd1dc416294f6d0217ce23779811ba43adc61be78462a236959b9ba94a"` [INFO] running `"docker" "rm" "-f" "80ea93cd1dc416294f6d0217ce23779811ba43adc61be78462a236959b9ba94a"` [INFO] [stdout] 80ea93cd1dc416294f6d0217ce23779811ba43adc61be78462a236959b9ba94a [INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+1.37.0" "test" "--frozen" "--no-run"` [INFO] [stdout] 4d8bfae25b0dc2a2bc69e653bcf264320b1585b0bb88931987d39b80c81d84dc [INFO] running `"docker" "start" "-a" "4d8bfae25b0dc2a2bc69e653bcf264320b1585b0bb88931987d39b80c81d84dc"` [INFO] [stderr] Compiling billbe v0.1.0 (/opt/crater/workdir) [INFO] [stderr] warning: unused `#[macro_use]` import [INFO] [stderr] --> src/main.rs:4:1 [INFO] [stderr] | [INFO] [stderr] 4 | #[macro_use] [INFO] [stderr] | ^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_imports)] on by default [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/rtc.rs:91:28 [INFO] [stderr] | [INFO] [stderr] 91 | (DATA_PORT, 0xe...0xff) => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] | [INFO] [stderr] = note: #[warn(ellipsis_inclusive_range_patterns)] on by default [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/rtc.rs:125:28 [INFO] [stderr] | [INFO] [stderr] 125 | (DATA_PORT, 0xe...0xff) => Ok(()), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: unused imports: `Arc`, `Mutex` [INFO] [stderr] --> src/main.rs:17:17 [INFO] [stderr] | [INFO] [stderr] 17 | use std::sync::{Arc, Mutex}; [INFO] [stderr] | ^^^ ^^^^^ [INFO] [stderr] [INFO] [stderr] warning: unused imports: `HttpRouter`, `Nickel` [INFO] [stderr] --> src/main.rs:22:14 [INFO] [stderr] | [INFO] [stderr] 22 | use nickel::{Nickel, HttpRouter}; [INFO] [stderr] | ^^^^^^ ^^^^^^^^^^ [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:244:26 [INFO] [stderr] | [INFO] [stderr] 244 | rtc::ADDR_LOW...rtc::ADDR_HIGH => self.rtc.read(addr, data), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:245:23 [INFO] [stderr] | [INFO] [stderr] 245 | 0x800_0000...0x880_0000 => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:290:26 [INFO] [stderr] | [INFO] [stderr] 290 | rtc::ADDR_LOW...rtc::ADDR_HIGH => self.rtc.write(addr, data), [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: `...` range patterns are deprecated [INFO] [stderr] --> src/main.rs:291:23 [INFO] [stderr] | [INFO] [stderr] 291 | 0x800_0000...0x880_0000 => { [INFO] [stderr] | ^^^ help: use `..=` for an inclusive range [INFO] [stderr] [INFO] [stderr] warning: unreachable expression [INFO] [stderr] --> src/hobbit/mmu.rs:193:17 [INFO] [stderr] | [INFO] [stderr] 193 | / return return Err(Error::BusFault { [INFO] [stderr] 194 | | address: addr, [INFO] [stderr] 195 | | mode: Mode::Read, [INFO] [stderr] 196 | | description: BusDescription::PageTableIsNotBacked, [INFO] [stderr] 197 | | }); [INFO] [stderr] | |____________________________________^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unreachable_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused import: `Write` [INFO] [stderr] --> src/main.rs:16:22 [INFO] [stderr] | [INFO] [stderr] 16 | use std::fmt::{self, Write}; [INFO] [stderr] | ^^^^^ [INFO] [stderr] [INFO] [stderr] warning: unused variable: `len` [INFO] [stderr] --> src/hobbit/mod.rs:746:13 [INFO] [stderr] | [INFO] [stderr] 746 | let len = self.pc.0 - self.instruction_pc.0; [INFO] [stderr] | ^^^ help: consider prefixing with an underscore: `_len` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_variables)] on by default [INFO] [stderr] [INFO] [stderr] warning: function is never used: `send_index` [INFO] [stderr] --> src/main.rs:445:1 [INFO] [stderr] | [INFO] [stderr] 445 | / fn send_index<'a, D>(_: &mut nickel::Request, [INFO] [stderr] 446 | | res: nickel::Response<'a, D>) [INFO] [stderr] 447 | | -> nickel::MiddlewareResult<'a, D> { [INFO] [stderr] 448 | | let index = std::path::Path::new("web/index.html"); [INFO] [stderr] 449 | | res.send_file(index) [INFO] [stderr] 450 | | } [INFO] [stderr] | |_^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(dead_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: the `mode:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:724:25 [INFO] [stderr] | [INFO] [stderr] 724 | mode: mode, [INFO] [stderr] | -----^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] | [INFO] [stderr] = note: #[warn(non_shorthand_field_patterns)] on by default [INFO] [stderr] [INFO] [stderr] warning: the `description:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:725:25 [INFO] [stderr] | [INFO] [stderr] 725 | description: description, [INFO] [stderr] | ------------^^^^^^^^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] warning: unused `std::result::Result` that must be used [INFO] [stderr] --> src/hobbit/mod.rs:750:9 [INFO] [stderr] | [INFO] [stderr] 750 | self.explain(instruction, memory, symbols); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_must_use)] on by default [INFO] [stderr] = note: this `Result` may be an `Err` variant, which should be handled [INFO] [stderr] [INFO] [stderr] warning: the `mode:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:817:24 [INFO] [stderr] | [INFO] [stderr] 817 | mode: mode, [INFO] [stderr] | -----^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] warning: the `description:` in this pattern is redundant [INFO] [stderr] --> src/hobbit/mod.rs:818:24 [INFO] [stderr] | [INFO] [stderr] 818 | description: description, [INFO] [stderr] | ------------^^^^^^^^^^^^ [INFO] [stderr] | | [INFO] [stderr] | help: remove this [INFO] [stderr] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 1.86s [INFO] running `"docker" "inspect" "4d8bfae25b0dc2a2bc69e653bcf264320b1585b0bb88931987d39b80c81d84dc"` [INFO] running `"docker" "rm" "-f" "4d8bfae25b0dc2a2bc69e653bcf264320b1585b0bb88931987d39b80c81d84dc"` [INFO] [stdout] 4d8bfae25b0dc2a2bc69e653bcf264320b1585b0bb88931987d39b80c81d84dc [INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/csherratt/BillBe:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+1.37.0" "test" "--frozen"` [INFO] [stdout] d9a55ef47c8b7730f56c980951f57baeecdbda5f9896c9018dc22112306bbcdb [INFO] running `"docker" "start" "-a" "d9a55ef47c8b7730f56c980951f57baeecdbda5f9896c9018dc22112306bbcdb"` [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 0.08s [INFO] [stderr] Running /opt/crater/target/debug/deps/billbe-3a35f5cad657157e [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 [INFO] [stdout] [INFO] running `"docker" "inspect" "d9a55ef47c8b7730f56c980951f57baeecdbda5f9896c9018dc22112306bbcdb"` [INFO] running `"docker" "rm" "-f" "d9a55ef47c8b7730f56c980951f57baeecdbda5f9896c9018dc22112306bbcdb"` [INFO] [stdout] d9a55ef47c8b7730f56c980951f57baeecdbda5f9896c9018dc22112306bbcdb