[INFO] cloning repository https://github.com/jelford/project_euler
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jelford/project_euler" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjelford%2Fproject_euler", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjelford%2Fproject_euler'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b7cdcc12bd242142680e4b73c43fdb1605404b77
[INFO] checking jelford/project_euler against master#b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18 for pr-79470
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjelford%2Fproject_euler" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jelford/project_euler on toolchain b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jelford/project_euler
[INFO] finished tweaking git repo https://github.com/jelford/project_euler
[INFO] tweaked toml for git repo https://github.com/jelford/project_euler written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/jelford/project_euler already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 426ba5461a08dbd1afeea51cffc708830ec02173c8144393e6c2b430c28ec3a8
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "426ba5461a08dbd1afeea51cffc708830ec02173c8144393e6c2b430c28ec3a8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "426ba5461a08dbd1afeea51cffc708830ec02173c8144393e6c2b430c28ec3a8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "426ba5461a08dbd1afeea51cffc708830ec02173c8144393e6c2b430c28ec3a8", kill_on_drop: false }`
[INFO] [stdout] 426ba5461a08dbd1afeea51cffc708830ec02173c8144393e6c2b430c28ec3a8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cf3c4ebd38fa8851847ca4f31eb585c380139819f0acf02f56a64e63ee649116
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "cf3c4ebd38fa8851847ca4f31eb585c380139819f0acf02f56a64e63ee649116", kill_on_drop: false }`
[INFO] [stderr]     Checking project_euler v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/palindromes.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |             mem::replace(&mut self.current_digits, updated);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/palindromes.rs:66:13
[INFO] [stdout]    |
[INFO] [stdout] 66 |             mem::replace(&mut self.current_digits, updated);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.92s
[INFO] running `Command { std: "docker" "inspect" "cf3c4ebd38fa8851847ca4f31eb585c380139819f0acf02f56a64e63ee649116", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf3c4ebd38fa8851847ca4f31eb585c380139819f0acf02f56a64e63ee649116", kill_on_drop: false }`
[INFO] [stdout] cf3c4ebd38fa8851847ca4f31eb585c380139819f0acf02f56a64e63ee649116