[INFO] cloning repository https://github.com/icostin/halfbit
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/icostin/halfbit" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ficostin%2Fhalfbit", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ficostin%2Fhalfbit'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 39b45887c42261217b9d5672f5ac3f6c9807915e
[INFO] checking icostin/halfbit against master#31ee872db5aae4750e3da1ca4ed1523c4356947f for pr-78461
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ficostin%2Fhalfbit" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/icostin/halfbit on toolchain 31ee872db5aae4750e3da1ca4ed1523c4356947f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/icostin/halfbit
[INFO] removed 0 missing examples
[INFO] finished tweaking git repo https://github.com/icostin/halfbit
[INFO] tweaked toml for git repo https://github.com/icostin/halfbit written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/icostin/halfbit already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e49b1f37d2e2ff0ba892fddc3831398d2100401e16dd4eb4877c1633396b4535
[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" "e49b1f37d2e2ff0ba892fddc3831398d2100401e16dd4eb4877c1633396b4535", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e49b1f37d2e2ff0ba892fddc3831398d2100401e16dd4eb4877c1633396b4535", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e49b1f37d2e2ff0ba892fddc3831398d2100401e16dd4eb4877c1633396b4535", kill_on_drop: false }`
[INFO] [stdout] e49b1f37d2e2ff0ba892fddc3831398d2100401e16dd4eb4877c1633396b4535
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8813317a33a842eb413be649eb893b713ffed674164a461201c97f0e54ed721
[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" "b8813317a33a842eb413be649eb893b713ffed674164a461201c97f0e54ed721", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.79
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling num-bigint v0.3.0
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling num-rational v0.3.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking num-complex v0.3.0
[INFO] [stderr]     Checking num v0.3.0
[INFO] [stderr]     Checking halfbit v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field is never read: `size`
[INFO] [stdout]   --> src/mm/layout.rs:51:5
[INFO] [stdout]    |
[INFO] [stdout] 51 |     size: NonZeroUsize,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `align`
[INFO] [stdout]   --> src/mm/layout.rs:52:5
[INFO] [stdout]    |
[INFO] [stdout] 52 |     align: Pow2Usize,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field is never read: `raw_allocator`
[INFO] [stdout]   --> src/mm/alloc/mod.rs:39:5
[INFO] [stdout]    |
[INFO] [stdout] 39 |     raw_allocator: &'a dyn RawAllocator
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `as_ref`
[INFO] [stdout]   --> src/mm/alloc/mod.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 |     fn as_ref(&mut self) -> AllocatorRef {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/mm/alloc/null.rs:33:13
[INFO] [stdout]    |
[INFO] [stdout] 33 |         let mut nra = NullRawAllocator{};
[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: field is never read: `raw_allocator`
[INFO] [stdout]   --> src/mm/alloc/mod.rs:39:5
[INFO] [stdout]    |
[INFO] [stdout] 39 |     raw_allocator: &'a dyn RawAllocator
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `as_ref`
[INFO] [stdout]   --> src/mm/alloc/mod.rs:49:8
[INFO] [stdout]    |
[INFO] [stdout] 49 |     fn as_ref(&mut self) -> AllocatorRef {
[INFO] [stdout]    |        ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 13.85s
[INFO] running `Command { std: "docker" "inspect" "b8813317a33a842eb413be649eb893b713ffed674164a461201c97f0e54ed721", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8813317a33a842eb413be649eb893b713ffed674164a461201c97f0e54ed721", kill_on_drop: false }`
[INFO] [stdout] b8813317a33a842eb413be649eb893b713ffed674164a461201c97f0e54ed721