[INFO] fetching crate ditto 0.2.0...
[INFO] checking ditto-0.2.0 against master#39b841dfe36f90a7cd111e7f0c55f32594f6e578 for pr-77035
[INFO] extracting crate ditto 0.2.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate ditto 0.2.0 on toolchain 39b841dfe36f90a7cd111e7f0c55f32594f6e578
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39b841dfe36f90a7cd111e7f0c55f32594f6e578" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ditto 0.2.0
[INFO] finished tweaking crates.io crate ditto 0.2.0
[INFO] tweaked toml for crates.io crate ditto 0.2.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39b841dfe36f90a7cd111e7f0c55f32594f6e578" "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" "+39b841dfe36f90a7cd111e7f0c55f32594f6e578" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+39b841dfe36f90a7cd111e7f0c55f32594f6e578" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a20fe9f0979b4f53cf0290e9bf9bc22b0adf3c62e1d1acc00bd27ebef534f3e0
[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" "a20fe9f0979b4f53cf0290e9bf9bc22b0adf3c62e1d1acc00bd27ebef534f3e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a20fe9f0979b4f53cf0290e9bf9bc22b0adf3c62e1d1acc00bd27ebef534f3e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a20fe9f0979b4f53cf0290e9bf9bc22b0adf3c62e1d1acc00bd27ebef534f3e0", kill_on_drop: false }`
[INFO] [stdout] a20fe9f0979b4f53cf0290e9bf9bc22b0adf3c62e1d1acc00bd27ebef534f3e0
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+39b841dfe36f90a7cd111e7f0c55f32594f6e578" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d76f9ddad7e24635f48df8b5944fd5c50314c9c64dea9d8f4f5465c593d1810b
[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" "d76f9ddad7e24635f48df8b5944fd5c50314c9c64dea9d8f4f5465c593d1810b", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]     Checking ryu v1.0.5
[INFO] [stderr]     Checking num-integer v0.1.44
[INFO] [stderr]     Checking num-complex v0.1.43
[INFO] [stderr]     Checking rmp v0.8.9
[INFO] [stderr]    Compiling syn v1.0.54
[INFO] [stderr]     Checking rmp-serde v0.13.7
[INFO] [stderr]     Checking serde_json v1.0.60
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking num-bigint v0.1.44
[INFO] [stderr]     Checking num-rational v0.1.42
[INFO] [stderr]     Checking num v0.1.42
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]     Checking ditto v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/tree.rs:382:13
[INFO] [stdout]     |
[INFO] [stdout] 382 |             mem::replace(self, child);
[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: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/tree.rs:382:13
[INFO] [stdout]     |
[INFO] [stdout] 382 |             mem::replace(self, child);
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 33.09s
[INFO] running `Command { std: "docker" "inspect" "d76f9ddad7e24635f48df8b5944fd5c50314c9c64dea9d8f4f5465c593d1810b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d76f9ddad7e24635f48df8b5944fd5c50314c9c64dea9d8f4f5465c593d1810b", kill_on_drop: false }`
[INFO] [stdout] d76f9ddad7e24635f48df8b5944fd5c50314c9c64dea9d8f4f5465c593d1810b