[INFO] cloning repository https://github.com/mjl152/rust-euler
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mjl152/rust-euler" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmjl152%2Frust-euler", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmjl152%2Frust-euler'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cf3eed55ee1ace81d88f24764707341ef0df4aa7
[INFO] checking mjl152/rust-euler against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmjl152%2Frust-euler" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mjl152/rust-euler on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mjl152/rust-euler
[INFO] finished tweaking git repo https://github.com/mjl152/rust-euler
[INFO] tweaked toml for git repo https://github.com/mjl152/rust-euler written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/mjl152/rust-euler already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: the lock file /workspace/builds/worker-6/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3e3b6f6e4108fb33e226e29bf424746fec8bf3a8ffad887db28150a8d9994230
[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" "3e3b6f6e4108fb33e226e29bf424746fec8bf3a8ffad887db28150a8d9994230", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3e3b6f6e4108fb33e226e29bf424746fec8bf3a8ffad887db28150a8d9994230", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3e3b6f6e4108fb33e226e29bf424746fec8bf3a8ffad887db28150a8d9994230", kill_on_drop: false }`
[INFO] [stdout] 3e3b6f6e4108fb33e226e29bf424746fec8bf3a8ffad887db28150a8d9994230
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 7b154c833fa14738c4be6e05c560ced4623014e0b2c31904fc1850969ec2f15a
[INFO] running `Command { std: "docker" "start" "-a" "7b154c833fa14738c4be6e05c560ced4623014e0b2c31904fc1850969ec2f15a", kill_on_drop: false }`
[INFO] [stderr]     Checking utf8-ranges v0.1.3
[INFO] [stderr]     Checking regex-syntax v0.3.9
[INFO] [stderr]     Checking strsim v0.5.2
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]     Checking memchr v0.1.11
[INFO] [stderr]     Checking time v0.1.44
[INFO] [stderr]     Checking thread-id v2.0.0
[INFO] [stderr]     Checking thread_local v0.2.7
[INFO] [stderr]     Checking aho-corasick v0.5.3
[INFO] [stderr]     Checking regex v0.1.80
[INFO] [stderr]     Checking num v0.1.42
[INFO] [stderr]     Checking docopt v0.6.86
[INFO] [stderr]     Checking rust_euler v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:47:6
[INFO] [stdout]    |
[INFO] [stdout] 47 |     for i in 0..iterations {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:33:6
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let mut problem : fn() -> Option<u64>;
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `i`
[INFO] [stdout]   --> src/main.rs:47:6
[INFO] [stdout]    |
[INFO] [stdout] 47 |     for i in 0..iterations {
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_i`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:33:6
[INFO] [stdout]    |
[INFO] [stdout] 33 |     let mut problem : fn() -> Option<u64>;
[INFO] [stdout]    |         ----^^^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.79s
[INFO] running `Command { std: "docker" "inspect" "7b154c833fa14738c4be6e05c560ced4623014e0b2c31904fc1850969ec2f15a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b154c833fa14738c4be6e05c560ced4623014e0b2c31904fc1850969ec2f15a", kill_on_drop: false }`
[INFO] [stdout] 7b154c833fa14738c4be6e05c560ced4623014e0b2c31904fc1850969ec2f15a