[INFO] fetching crate fff 0.2.2...
[INFO] checking fff-0.2.2 against master#e1beee4992ad4b235fc700bf7af1ee86f894ea53 for pr-74130
[INFO] extracting crate fff 0.2.2 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate fff 0.2.2 on toolchain e1beee4992ad4b235fc700bf7af1ee86f894ea53
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate fff 0.2.2
[INFO] finished tweaking crates.io crate fff 0.2.2
[INFO] tweaked toml for crates.io crate fff 0.2.2 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "metadata" "--no-deps" "--format-version=1", 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] 2f657058282c1ee053f0bc2760ec5d0ca820bf0c49fda72d57c846fab8454c71
[INFO] running `Command { std: "docker" "start" "-a" "2f657058282c1ee053f0bc2760ec5d0ca820bf0c49fda72d57c846fab8454c71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f657058282c1ee053f0bc2760ec5d0ca820bf0c49fda72d57c846fab8454c71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f657058282c1ee053f0bc2760ec5d0ca820bf0c49fda72d57c846fab8454c71", kill_on_drop: false }`
[INFO] [stdout] 2f657058282c1ee053f0bc2760ec5d0ca820bf0c49fda72d57c846fab8454c71
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+e1beee4992ad4b235fc700bf7af1ee86f894ea53" "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] 6bf1c7825c6b25fa5da71db459898c332b70f8451edb940e2721843fa0220aea
[INFO] running `Command { std: "docker" "start" "-a" "6bf1c7825c6b25fa5da71db459898c332b70f8451edb940e2721843fa0220aea", kill_on_drop: false }`
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling cc v1.0.58
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]    Compiling fff v0.2.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/asm.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     std::mem::replace(a, res);
[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/asm.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     std::mem::replace(a, res);
[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 4.71s
[INFO] running `Command { std: "docker" "inspect" "6bf1c7825c6b25fa5da71db459898c332b70f8451edb940e2721843fa0220aea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6bf1c7825c6b25fa5da71db459898c332b70f8451edb940e2721843fa0220aea", kill_on_drop: false }`
[INFO] [stdout] 6bf1c7825c6b25fa5da71db459898c332b70f8451edb940e2721843fa0220aea