[INFO] fetching crate futures-join-macro-preview 0.3.0-alpha.19...
[INFO] checking futures-join-macro-preview-0.3.0-alpha.19 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate futures-join-macro-preview 0.3.0-alpha.19 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate futures-join-macro-preview 0.3.0-alpha.19 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate futures-join-macro-preview 0.3.0-alpha.19
[INFO] finished tweaking crates.io crate futures-join-macro-preview 0.3.0-alpha.19
[INFO] tweaked toml for crates.io crate futures-join-macro-preview 0.3.0-alpha.19 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "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] 6e939cfc1257e3be710a8c6ba922913e09f1ca65b580ec896aaffba5dfac931d
[INFO] running `Command { std: "docker" "start" "-a" "6e939cfc1257e3be710a8c6ba922913e09f1ca65b580ec896aaffba5dfac931d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6e939cfc1257e3be710a8c6ba922913e09f1ca65b580ec896aaffba5dfac931d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6e939cfc1257e3be710a8c6ba922913e09f1ca65b580ec896aaffba5dfac931d", kill_on_drop: false }`
[INFO] [stdout] 6e939cfc1257e3be710a8c6ba922913e09f1ca65b580ec896aaffba5dfac931d
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6f5107d92e6f9cc04e338e7868431e39d6ca1e523ccd5645127e73ab687ea73a
[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" "6f5107d92e6f9cc04e338e7868431e39d6ca1e523ccd5645127e73ab687ea73a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]     Checking unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]     Checking quote v1.0.9
[INFO] [stderr]     Checking futures-join-macro-preview v0.3.0-alpha.19 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused extern crate
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | extern crate proc_macro;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> src/lib.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![warn(rust_2018_idioms, unreachable_pub)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]   = note: `#[warn(unused_extern_crates)]` implied by `#[warn(rust_2018_idioms)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused extern crate
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | extern crate proc_macro;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> src/lib.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![warn(rust_2018_idioms, unreachable_pub)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^
[INFO] [stdout]   = note: `#[warn(unused_extern_crates)]` implied by `#[warn(rust_2018_idioms)]`
[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 4.52s
[INFO] running `Command { std: "docker" "inspect" "6f5107d92e6f9cc04e338e7868431e39d6ca1e523ccd5645127e73ab687ea73a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f5107d92e6f9cc04e338e7868431e39d6ca1e523ccd5645127e73ab687ea73a", kill_on_drop: false }`
[INFO] [stdout] 6f5107d92e6f9cc04e338e7868431e39d6ca1e523ccd5645127e73ab687ea73a