[INFO] fetching crate detach 0.0.42...
[INFO] checking detach-0.0.42 against try#6f12b8fe67b4eed2e838dab803ed9493b9d62c0f for pr-79073
[INFO] extracting crate detach 0.0.42 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate detach 0.0.42 on toolchain 6f12b8fe67b4eed2e838dab803ed9493b9d62c0f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate detach 0.0.42
[INFO] finished tweaking crates.io crate detach 0.0.42
[INFO] tweaked toml for crates.io crate detach 0.0.42 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "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] 975263a84312b9f7fc5c515873aabd05c4f42ff16236c7f7e66594a534790c3a
[INFO] running `Command { std: "docker" "start" "-a" "975263a84312b9f7fc5c515873aabd05c4f42ff16236c7f7e66594a534790c3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "975263a84312b9f7fc5c515873aabd05c4f42ff16236c7f7e66594a534790c3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "975263a84312b9f7fc5c515873aabd05c4f42ff16236c7f7e66594a534790c3a", kill_on_drop: false }`
[INFO] [stdout] 975263a84312b9f7fc5c515873aabd05c4f42ff16236c7f7e66594a534790c3a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+6f12b8fe67b4eed2e838dab803ed9493b9d62c0f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 02dff7133f26e2653aaa6f8d2a39dc5b40b97b128940490c4785e083efa4bc95
[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" "02dff7133f26e2653aaa6f8d2a39dc5b40b97b128940490c4785e083efa4bc95", kill_on_drop: false }`
[INFO] [stderr]     Checking detach v0.0.42 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:169:9
[INFO] [stdout]     |
[INFO] [stdout] 169 |         std::mem::replace(&mut self.0, Some(t));
[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:169:9
[INFO] [stdout]     |
[INFO] [stdout] 169 |         std::mem::replace(&mut self.0, Some(t));
[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 0.86s
[INFO] running `Command { std: "docker" "inspect" "02dff7133f26e2653aaa6f8d2a39dc5b40b97b128940490c4785e083efa4bc95", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "02dff7133f26e2653aaa6f8d2a39dc5b40b97b128940490c4785e083efa4bc95", kill_on_drop: false }`
[INFO] [stdout] 02dff7133f26e2653aaa6f8d2a39dc5b40b97b128940490c4785e083efa4bc95