[INFO] fetching crate big_unsigned_ints 0.1.6...
[INFO] testing big_unsigned_ints-0.1.6 against 1.90.0 for beta-1.91-3
[INFO] extracting crate big_unsigned_ints 0.1.6 into /workspace/builds/worker-1-tc1/source
[INFO] started tweaking crates.io crate big_unsigned_ints 0.1.6
[INFO] finished tweaking crates.io crate big_unsigned_ints 0.1.6
[INFO] tweaked toml for crates.io crate big_unsigned_ints 0.1.6 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate big_unsigned_ints 0.1.6 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate big_unsigned_ints 0.1.6 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" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 42ed4c134686ff2be514e03f93d2267f53afe814e2b16432397f3d43f555fb2b
[INFO] running `Command { std: "docker" "start" "-a" "42ed4c134686ff2be514e03f93d2267f53afe814e2b16432397f3d43f555fb2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "42ed4c134686ff2be514e03f93d2267f53afe814e2b16432397f3d43f555fb2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42ed4c134686ff2be514e03f93d2267f53afe814e2b16432397f3d43f555fb2b", kill_on_drop: false }`
[INFO] [stdout] 42ed4c134686ff2be514e03f93d2267f53afe814e2b16432397f3d43f555fb2b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6682ca58435cbb3278bbb7c0965ad0c182e672f4d0227ed380156caea6bbc4af
[INFO] running `Command { std: "docker" "start" "-a" "6682ca58435cbb3278bbb7c0965ad0c182e672f4d0227ed380156caea6bbc4af", kill_on_drop: false }`
[INFO] [stderr]    Compiling big_unsigned_ints v0.1.6 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:121:13
[INFO] [stdout]     |
[INFO] [stdout] 121 |             write!(f, "0x{:X} ", x[i]);
[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] 121 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:174:13
[INFO] [stdout]     |
[INFO] [stdout] 174 |             write!(f, "0x{:X} ", x[i]);
[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] 174 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:227:13
[INFO] [stdout]     |
[INFO] [stdout] 227 |             write!(f, "0x{:X} ", x[i]);
[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] 227 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:278:13
[INFO] [stdout]     |
[INFO] [stdout] 278 |             write!(f, "0x{:X} ", x[i]);
[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] 278 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:330:13
[INFO] [stdout]     |
[INFO] [stdout] 330 |             write!(f, "0x{:X} ", x[i]);
[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] 330 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "6682ca58435cbb3278bbb7c0965ad0c182e672f4d0227ed380156caea6bbc4af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6682ca58435cbb3278bbb7c0965ad0c182e672f4d0227ed380156caea6bbc4af", kill_on_drop: false }`
[INFO] [stdout] 6682ca58435cbb3278bbb7c0965ad0c182e672f4d0227ed380156caea6bbc4af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1cb2922884d1b364d81170c6f94459b4998db8f4d16e6ea724629a32ee819e96
[INFO] running `Command { std: "docker" "start" "-a" "1cb2922884d1b364d81170c6f94459b4998db8f4d16e6ea724629a32ee819e96", kill_on_drop: false }`
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:121:13
[INFO] [stdout]     |
[INFO] [stdout] 121 |             write!(f, "0x{:X} ", x[i]);
[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] 121 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling big_unsigned_ints v0.1.6 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:174:13
[INFO] [stdout]     |
[INFO] [stdout] 174 |             write!(f, "0x{:X} ", x[i]);
[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] 174 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:227:13
[INFO] [stdout]     |
[INFO] [stdout] 227 |             write!(f, "0x{:X} ", x[i]);
[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] 227 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:278:13
[INFO] [stdout]     |
[INFO] [stdout] 278 |             write!(f, "0x{:X} ", x[i]);
[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] 278 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:330:13
[INFO] [stdout]     |
[INFO] [stdout] 330 |             write!(f, "0x{:X} ", x[i]);
[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] 330 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:121:13
[INFO] [stdout]     |
[INFO] [stdout] 121 |             write!(f, "0x{:X} ", x[i]);
[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] 121 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:174:13
[INFO] [stdout]     |
[INFO] [stdout] 174 |             write!(f, "0x{:X} ", x[i]);
[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] 174 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:227:13
[INFO] [stdout]     |
[INFO] [stdout] 227 |             write!(f, "0x{:X} ", x[i]);
[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] 227 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:278:13
[INFO] [stdout]     |
[INFO] [stdout] 278 |             write!(f, "0x{:X} ", x[i]);
[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] 278 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:330:13
[INFO] [stdout]     |
[INFO] [stdout] 330 |             write!(f, "0x{:X} ", x[i]);
[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] 330 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.39s
[INFO] running `Command { std: "docker" "inspect" "1cb2922884d1b364d81170c6f94459b4998db8f4d16e6ea724629a32ee819e96", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1cb2922884d1b364d81170c6f94459b4998db8f4d16e6ea724629a32ee819e96", kill_on_drop: false }`
[INFO] [stdout] 1cb2922884d1b364d81170c6f94459b4998db8f4d16e6ea724629a32ee819e96
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] f61c41c46ffed1013203668fb3e350cd327920bf15f4b23167ef4e14a24c4985
[INFO] running `Command { std: "docker" "start" "-a" "f61c41c46ffed1013203668fb3e350cd327920bf15f4b23167ef4e14a24c4985", kill_on_drop: false }`
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/lib.rs:121:13
[INFO] [stderr]     |
[INFO] [stderr] 121 |             write!(f, "0x{:X} ", x[i]);
[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)]` on by default
[INFO] [stderr] help: use `let _ = ...` to ignore the resulting value
[INFO] [stderr]     |
[INFO] [stderr] 121 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stderr]     |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/lib.rs:174:13
[INFO] [stderr]     |
[INFO] [stderr] 174 |             write!(f, "0x{:X} ", x[i]);
[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] 174 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stderr]     |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/lib.rs:227:13
[INFO] [stderr]     |
[INFO] [stderr] 227 |             write!(f, "0x{:X} ", x[i]);
[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] 227 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stderr]     |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/lib.rs:278:13
[INFO] [stderr]     |
[INFO] [stderr] 278 |             write!(f, "0x{:X} ", x[i]);
[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] 278 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stderr]     |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]    --> src/lib.rs:330:13
[INFO] [stderr]     |
[INFO] [stderr] 330 |             write!(f, "0x{:X} ", x[i]);
[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] 330 |             let _ = write!(f, "0x{:X} ", x[i]);
[INFO] [stderr]     |             +++++++
[INFO] [stderr] 
[INFO] [stderr] warning: `big_unsigned_ints` (lib) generated 5 warnings
[INFO] [stderr] warning: `big_unsigned_ints` (lib test) generated 5 warnings (5 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/big_unsigned_ints-cbafe37b3e2b6a75)
[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 tests/integration_tests.rs (/opt/rustwide/target/debug/deps/integration_tests-cfae621fb2a14029)
[INFO] [stdout] 
[INFO] [stdout] running 4 tests
[INFO] [stdout] test bytes_to_u256 ... ok
[INFO] [stdout] test instantiate_u256 ... ok
[INFO] [stdout] test u256_into_bytes ... ok
[INFO] [stdout] test instantiate_u384 ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests big_unsigned_ints
[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" "f61c41c46ffed1013203668fb3e350cd327920bf15f4b23167ef4e14a24c4985", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f61c41c46ffed1013203668fb3e350cd327920bf15f4b23167ef4e14a24c4985", kill_on_drop: false }`
[INFO] [stdout] f61c41c46ffed1013203668fb3e350cd327920bf15f4b23167ef4e14a24c4985