[INFO] fetching crate concurrency 4.20.1...
[INFO] checking concurrency-4.20.1 against master#0d37dca25a51fb900a402c94c8818ad1c2789e30 for pr-77526
[INFO] extracting crate concurrency 4.20.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate concurrency 4.20.1 on toolchain 0d37dca25a51fb900a402c94c8818ad1c2789e30
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate concurrency 4.20.1
[INFO] finished tweaking crates.io crate concurrency 4.20.1
[INFO] tweaked toml for crates.io crate concurrency 4.20.1 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate concurrency 4.20.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 534c315ad639215b836d3c0efd3b84611a397c649e9b04d288dfb469d33efc7b
[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" "534c315ad639215b836d3c0efd3b84611a397c649e9b04d288dfb469d33efc7b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "534c315ad639215b836d3c0efd3b84611a397c649e9b04d288dfb469d33efc7b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "534c315ad639215b836d3c0efd3b84611a397c649e9b04d288dfb469d33efc7b", kill_on_drop: false }`
[INFO] [stdout] 534c315ad639215b836d3c0efd3b84611a397c649e9b04d288dfb469d33efc7b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4201f73c625e774e3cc86ff9335bde3f42c806da10b19b1fc8e376455176a952
[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" "4201f73c625e774e3cc86ff9335bde3f42c806da10b19b1fc8e376455176a952", kill_on_drop: false }`
[INFO] [stderr]     Checking concurrency v4.20.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.10s
[INFO] running `Command { std: "docker" "inspect" "4201f73c625e774e3cc86ff9335bde3f42c806da10b19b1fc8e376455176a952", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4201f73c625e774e3cc86ff9335bde3f42c806da10b19b1fc8e376455176a952", kill_on_drop: false }`
[INFO] [stdout] 4201f73c625e774e3cc86ff9335bde3f42c806da10b19b1fc8e376455176a952