[INFO] fetching crate chainmap 0.1.2...
[INFO] checking chainmap-0.1.2 against master#d62d3f7fa9a91d933213cc10e20e740608983f64 for pr-77015
[INFO] extracting crate chainmap 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate chainmap 0.1.2 on toolchain d62d3f7fa9a91d933213cc10e20e740608983f64
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate chainmap 0.1.2
[INFO] finished tweaking crates.io crate chainmap 0.1.2
[INFO] tweaked toml for crates.io crate chainmap 0.1.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4ef52948a632fd3dc64a00c9d7395211e93bbe5ea8fc1054bbe118149a7a970d
[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" "4ef52948a632fd3dc64a00c9d7395211e93bbe5ea8fc1054bbe118149a7a970d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4ef52948a632fd3dc64a00c9d7395211e93bbe5ea8fc1054bbe118149a7a970d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ef52948a632fd3dc64a00c9d7395211e93bbe5ea8fc1054bbe118149a7a970d", kill_on_drop: false }`
[INFO] [stdout] 4ef52948a632fd3dc64a00c9d7395211e93bbe5ea8fc1054bbe118149a7a970d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 41b16ae072050063990c925ab0627b999daaa093b7b501a3ade3472c7bf55a4f
[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" "41b16ae072050063990c925ab0627b999daaa093b7b501a3ade3472c7bf55a4f", kill_on_drop: false }`
[INFO] [stderr]     Checking chainmap v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:331:9
[INFO] [stdout]     |
[INFO] [stdout] 331 |         std::mem::replace(&mut *self, oldlevel);
[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/lib.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:331:9
[INFO] [stdout]     |
[INFO] [stdout] 331 |         std::mem::replace(&mut *self, oldlevel);
[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/lib.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[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: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.92s
[INFO] running `Command { std: "docker" "inspect" "41b16ae072050063990c925ab0627b999daaa093b7b501a3ade3472c7bf55a4f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "41b16ae072050063990c925ab0627b999daaa093b7b501a3ade3472c7bf55a4f", kill_on_drop: false }`
[INFO] [stdout] 41b16ae072050063990c925ab0627b999daaa093b7b501a3ade3472c7bf55a4f