[INFO] cloning repository https://github.com/saadjhk/rusty_chain
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/saadjhk/rusty_chain" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsaadjhk%2Frusty_chain", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsaadjhk%2Frusty_chain'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 876c273feadc8a6182b4a1932a7afbb6bdb2d516
[INFO] testing saadjhk/rusty_chain against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsaadjhk%2Frusty_chain" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/saadjhk/rusty_chain on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/saadjhk/rusty_chain
[INFO] finished tweaking git repo https://github.com/saadjhk/rusty_chain
[INFO] tweaked toml for git repo https://github.com/saadjhk/rusty_chain written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/saadjhk/rusty_chain already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8c24a8fe75c78fc0c27c607cc896c59bc2f89d6ad009da1a875ab42fe50b7b55
[INFO] running `Command { std: "docker" "start" "-a" "8c24a8fe75c78fc0c27c607cc896c59bc2f89d6ad009da1a875ab42fe50b7b55", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c24a8fe75c78fc0c27c607cc896c59bc2f89d6ad009da1a875ab42fe50b7b55", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c24a8fe75c78fc0c27c607cc896c59bc2f89d6ad009da1a875ab42fe50b7b55", kill_on_drop: false }`
[INFO] [stdout] 8c24a8fe75c78fc0c27c607cc896c59bc2f89d6ad009da1a875ab42fe50b7b55
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d5760f0eebac4546e7d4c4abcd89cb92f4d2d4f69d27450503d67b74718ae5fd
[INFO] running `Command { std: "docker" "start" "-a" "d5760f0eebac4546e7d4c4abcd89cb92f4d2d4f69d27450503d67b74718ae5fd", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling cpuid-bool v0.1.2
[INFO] [stderr]    Compiling opaque-debug v0.3.0
[INFO] [stderr]    Compiling generic-array v0.14.4
[INFO] [stderr]    Compiling digest v0.9.0
[INFO] [stderr]    Compiling block-buffer v0.9.0
[INFO] [stderr]    Compiling sha2 v0.9.3
[INFO] [stderr]    Compiling proj_one v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib/block.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |         write!(f, "Prev Block Hash: ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:49:13
[INFO] [stdout]    |
[INFO] [stdout] 49 |             write!(f, "{:x}", byte);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |         write!(f, "\nBlock Hash: ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:54:13
[INFO] [stdout]    |
[INFO] [stdout] 54 |             write!(f, "{:x}", byte);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.84s
[INFO] running `Command { std: "docker" "inspect" "d5760f0eebac4546e7d4c4abcd89cb92f4d2d4f69d27450503d67b74718ae5fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d5760f0eebac4546e7d4c4abcd89cb92f4d2d4f69d27450503d67b74718ae5fd", kill_on_drop: false }`
[INFO] [stdout] d5760f0eebac4546e7d4c4abcd89cb92f4d2d4f69d27450503d67b74718ae5fd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9164a11d0b7bf11eeaf5c39ce7b9ff811a89d37fce305fd0601f0500cb3cac40
[INFO] running `Command { std: "docker" "start" "-a" "9164a11d0b7bf11eeaf5c39ce7b9ff811a89d37fce305fd0601f0500cb3cac40", kill_on_drop: false }`
[INFO] [stderr]    Compiling proj_one v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib/block.rs:47:9
[INFO] [stdout]    |
[INFO] [stdout] 47 |         write!(f, "Prev Block Hash: ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:49:13
[INFO] [stdout]    |
[INFO] [stdout] 49 |             write!(f, "{:x}", byte);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:52:9
[INFO] [stdout]    |
[INFO] [stdout] 52 |         write!(f, "\nBlock Hash: ");
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (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/lib/block.rs:54:13
[INFO] [stdout]    |
[INFO] [stdout] 54 |             write!(f, "{:x}", byte);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.35s
[INFO] running `Command { std: "docker" "inspect" "9164a11d0b7bf11eeaf5c39ce7b9ff811a89d37fce305fd0601f0500cb3cac40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9164a11d0b7bf11eeaf5c39ce7b9ff811a89d37fce305fd0601f0500cb3cac40", kill_on_drop: false }`
[INFO] [stdout] 9164a11d0b7bf11eeaf5c39ce7b9ff811a89d37fce305fd0601f0500cb3cac40
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 4f97ab1438f5121a6b76e2aa94adb5affe1dc45c9a36b4752c7d78d9325070ab
[INFO] running `Command { std: "docker" "start" "-a" "4f97ab1438f5121a6b76e2aa94adb5affe1dc45c9a36b4752c7d78d9325070ab", kill_on_drop: false }`
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/lib/block.rs:47:9
[INFO] [stderr]    |
[INFO] [stderr] 47 |         write!(f, "Prev Block Hash: ");
[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]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/lib/block.rs:49:13
[INFO] [stderr]    |
[INFO] [stderr] 49 |             write!(f, "{:x}", byte);
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/lib/block.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |         write!(f, "\nBlock Hash: ");
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `Result` that must be used
[INFO] [stderr]   --> src/lib/block.rs:54:13
[INFO] [stderr]    |
[INFO] [stderr] 54 |             write!(f, "{:x}", byte);
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this warning originates in the macro `write` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: `proj_one` (bin "proj_one" test) generated 4 warnings
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/proj_one-f6c842757b4c067a)
[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" "4f97ab1438f5121a6b76e2aa94adb5affe1dc45c9a36b4752c7d78d9325070ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f97ab1438f5121a6b76e2aa94adb5affe1dc45c9a36b4752c7d78d9325070ab", kill_on_drop: false }`
[INFO] [stdout] 4f97ab1438f5121a6b76e2aa94adb5affe1dc45c9a36b4752c7d78d9325070ab