[INFO] cloning repository https://github.com/domsim1/rusty-old-maid
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/domsim1/rusty-old-maid" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdomsim1%2Frusty-old-maid", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdomsim1%2Frusty-old-maid'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a105dc884329ba8d8ca5ac77a80a13b515f866d1
[INFO] checking domsim1/rusty-old-maid against master#9748d87dc70a9a6725c5dbd76ce29d04752b4f90 for pr-144156
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdomsim1%2Frusty-old-maid" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/domsim1/rusty-old-maid
[INFO] finished tweaking git repo https://github.com/domsim1/rusty-old-maid
[INFO] tweaked toml for git repo https://github.com/domsim1/rusty-old-maid written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/domsim1/rusty-old-maid on toolchain 9748d87dc70a9a6725c5dbd76ce29d04752b4f90
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+9748d87dc70a9a6725c5dbd76ce29d04752b4f90" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/domsim1/rusty-old-maid 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" "+9748d87dc70a9a6725c5dbd76ce29d04752b4f90" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+9748d87dc70a9a6725c5dbd76ce29d04752b4f90" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 05663271e2e1fecce6218436048ca55d89e20f318f25b4c93508bf74385761d0
[INFO] running `Command { std: "docker" "start" "-a" "05663271e2e1fecce6218436048ca55d89e20f318f25b4c93508bf74385761d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "05663271e2e1fecce6218436048ca55d89e20f318f25b4c93508bf74385761d0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "05663271e2e1fecce6218436048ca55d89e20f318f25b4c93508bf74385761d0", kill_on_drop: false }`
[INFO] [stdout] 05663271e2e1fecce6218436048ca55d89e20f318f25b4c93508bf74385761d0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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:cf8efcab8866f2cf4285301c7418e2f4f2a9b088c91ba69c40d5b659f81557f7" "/opt/rustwide/cargo-home/bin/cargo" "+9748d87dc70a9a6725c5dbd76ce29d04752b4f90" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d2e36845f8d562d834270bd6af05bcd9dfa63d861d8fa8df82316f02b49c355e
[INFO] running `Command { std: "docker" "start" "-a" "d2e36845f8d562d834270bd6af05bcd9dfa63d861d8fa8df82316f02b49c355e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking old-maid v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/fiftytwo.rs:138:9
[INFO] [stdout]     |
[INFO] [stdout] 138 |         &self.deck.shuffle(&mut thread_rng());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 138 |         let _ = &self.deck.shuffle(&mut thread_rng());
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/fiftytwo.rs:138:9
[INFO] [stdout]     |
[INFO] [stdout] 138 |         &self.deck.shuffle(&mut thread_rng());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 138 |         let _ = &self.deck.shuffle(&mut thread_rng());
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/fiftytwo.rs:143:13
[INFO] [stdout]     |
[INFO] [stdout] 143 |             &self.hands.push(Vec::new());
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 143 |             let _ = &self.hands.push(Vec::new());
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/fiftytwo.rs:143:13
[INFO] [stdout]     |
[INFO] [stdout] 143 |             &self.hands.push(Vec::new());
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 143 |             let _ = &self.hands.push(Vec::new());
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.33s
[INFO] running `Command { std: "docker" "inspect" "d2e36845f8d562d834270bd6af05bcd9dfa63d861d8fa8df82316f02b49c355e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d2e36845f8d562d834270bd6af05bcd9dfa63d861d8fa8df82316f02b49c355e", kill_on_drop: false }`
[INFO] [stdout] d2e36845f8d562d834270bd6af05bcd9dfa63d861d8fa8df82316f02b49c355e