[INFO] updating cached repository https://github.com/OffBlockway/OffBlockwayMiningClient
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 6fc1cfb70b1656b364916575b4405331ae0f6a8f
[INFO] checking OffBlockway/OffBlockwayMiningClient against master#c9edc02e8320a9e5799d185910ece7d491f524e6 for pr-64398
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FOffBlockway%2FOffBlockwayMiningClient" "work/builds/worker-7/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/OffBlockway/OffBlockwayMiningClient on toolchain c9edc02e8320a9e5799d185910ece7d491f524e6-alt
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/OffBlockway/OffBlockwayMiningClient
[INFO] finished tweaking git repo https://github.com/OffBlockway/OffBlockwayMiningClient
[INFO] tweaked toml for git repo https://github.com/OffBlockway/OffBlockwayMiningClient written to work/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/OffBlockway/OffBlockwayMiningClient already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/mnt/big/crater/work/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/mnt/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+c9edc02e8320a9e5799d185910ece7d491f524e6-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 79e95ccd76ff5f4c41b524610d999d4665227c5453ab5434cedbf5854b1b3064
[INFO] running `"docker" "start" "-a" "79e95ccd76ff5f4c41b524610d999d4665227c5453ab5434cedbf5854b1b3064"`
[INFO] [stderr]     Checking serde v1.0.24
[INFO] [stderr]     Checking generic-array v0.8.3
[INFO] [stderr]    Compiling serde_derive_internals v0.18.0
[INFO] [stderr]     Checking generic-array v0.9.0
[INFO] [stderr]     Checking chrono v0.4.0
[INFO] [stderr]     Checking block-buffer v0.2.0
[INFO] [stderr]     Checking digest v0.6.2
[INFO] [stderr]     Checking sha3 v0.6.0
[INFO] [stderr]    Compiling serde_derive v1.0.24
[INFO] [stderr]     Checking serde_json v1.0.8
[INFO] [stderr]     Checking off_blockway v0.0.8
[INFO] [stderr]     Checking mining_client v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:104:9
[INFO] [stderr]     |
[INFO] [stderr] 104 |         file.read_to_string( &mut buffer );
[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: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/main.rs:104:9
[INFO] [stderr]     |
[INFO] [stderr] 104 |         file.read_to_string( &mut buffer );
[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]     Finished dev [unoptimized + debuginfo] target(s) in 20.33s
[INFO] running `"docker" "inspect" "79e95ccd76ff5f4c41b524610d999d4665227c5453ab5434cedbf5854b1b3064"`
[INFO] running `"docker" "rm" "-f" "79e95ccd76ff5f4c41b524610d999d4665227c5453ab5434cedbf5854b1b3064"`
[INFO] [stdout] 79e95ccd76ff5f4c41b524610d999d4665227c5453ab5434cedbf5854b1b3064