[INFO] fetching crate fluid-let 0.1.0...
[INFO] checking fluid-let-0.1.0 against master#195ad4830e11a544391abe296b146450dea8411b for pr-82781
[INFO] extracting crate fluid-let 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate fluid-let 0.1.0 on toolchain 195ad4830e11a544391abe296b146450dea8411b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+195ad4830e11a544391abe296b146450dea8411b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate fluid-let 0.1.0
[INFO] finished tweaking crates.io crate fluid-let 0.1.0
[INFO] tweaked toml for crates.io crate fluid-let 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+195ad4830e11a544391abe296b146450dea8411b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+195ad4830e11a544391abe296b146450dea8411b" "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-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" "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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+195ad4830e11a544391abe296b146450dea8411b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ba96f6cc5e42d504e5da6d10d87febcc17eec41c5a6ef6220bd402cac88139ae
[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" "ba96f6cc5e42d504e5da6d10d87febcc17eec41c5a6ef6220bd402cac88139ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ba96f6cc5e42d504e5da6d10d87febcc17eec41c5a6ef6220bd402cac88139ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba96f6cc5e42d504e5da6d10d87febcc17eec41c5a6ef6220bd402cac88139ae", kill_on_drop: false }`
[INFO] [stdout] ba96f6cc5e42d504e5da6d10d87febcc17eec41c5a6ef6220bd402cac88139ae
[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" "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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+195ad4830e11a544391abe296b146450dea8411b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a784e73bc5854ea94d6cd2ba523722668df8e30540cafc732278333f13c9110f
[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" "a784e73bc5854ea94d6cd2ba523722668df8e30540cafc732278333f13c9110f", kill_on_drop: false }`
[INFO] [stderr]     Checking fluid-let v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:302:13
[INFO] [stdout]     |
[INFO] [stdout] 302 |             std::mem::replace(&mut *self.cell.cell.get(), self.old_value.take());
[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/lib.rs:302:13
[INFO] [stdout]     |
[INFO] [stdout] 302 |             std::mem::replace(&mut *self.cell.cell.get(), self.old_value.take());
[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 1.12s
[INFO] running `Command { std: "docker" "inspect" "a784e73bc5854ea94d6cd2ba523722668df8e30540cafc732278333f13c9110f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a784e73bc5854ea94d6cd2ba523722668df8e30540cafc732278333f13c9110f", kill_on_drop: false }`
[INFO] [stdout] a784e73bc5854ea94d6cd2ba523722668df8e30540cafc732278333f13c9110f