[INFO] fetching crate ur20-modbus 0.4.0...
[INFO] checking ur20-modbus-0.4.0 against try#9cfe725f0995b018340c519db1b2f3cf8a7e0631 for pr-81174
[INFO] extracting crate ur20-modbus 0.4.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate ur20-modbus 0.4.0 on toolchain 9cfe725f0995b018340c519db1b2f3cf8a7e0631
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9cfe725f0995b018340c519db1b2f3cf8a7e0631" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ur20-modbus 0.4.0
[INFO] finished tweaking crates.io crate ur20-modbus 0.4.0
[INFO] tweaked toml for crates.io crate ur20-modbus 0.4.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate ur20-modbus 0.4.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9cfe725f0995b018340c519db1b2f3cf8a7e0631" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded socket2 v0.3.11
[INFO] [stderr]   Downloaded arc-swap v0.4.4
[INFO] [stderr]   Downloaded ur20 v0.5.1
[INFO] [stderr]   Downloaded tokio-modbus v0.4.0
[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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9cfe725f0995b018340c519db1b2f3cf8a7e0631" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f2e6593cd37752d50295ea9bb3e2032d35e7a71769250bce06e0c48b6e1d9ed6
[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" "f2e6593cd37752d50295ea9bb3e2032d35e7a71769250bce06e0c48b6e1d9ed6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f2e6593cd37752d50295ea9bb3e2032d35e7a71769250bce06e0c48b6e1d9ed6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f2e6593cd37752d50295ea9bb3e2032d35e7a71769250bce06e0c48b6e1d9ed6", kill_on_drop: false }`
[INFO] [stdout] f2e6593cd37752d50295ea9bb3e2032d35e7a71769250bce06e0c48b6e1d9ed6
[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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9cfe725f0995b018340c519db1b2f3cf8a7e0631" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e3d4111876e759404834ae7c4375e3f5a635008630ba7af952973150a95e4cf4
[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" "e3d4111876e759404834ae7c4375e3f5a635008630ba7af952973150a95e4cf4", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking arc-swap v0.4.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]     Checking pin-project-lite v0.1.4
[INFO] [stderr]     Checking futures-task v0.3.4
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking smallvec v1.2.0
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.12.0
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]     Checking signal-hook-registry v1.2.0
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]     Checking ur20 v0.5.1
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]     Checking tokio v0.2.13
[INFO] [stderr]     Checking tokio-util v0.2.0
[INFO] [stderr]     Checking tokio-modbus v0.4.0
[INFO] [stderr]     Checking ur20-modbus v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 35.55s
[INFO] running `Command { std: "docker" "inspect" "e3d4111876e759404834ae7c4375e3f5a635008630ba7af952973150a95e4cf4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3d4111876e759404834ae7c4375e3f5a635008630ba7af952973150a95e4cf4", kill_on_drop: false }`
[INFO] [stdout] e3d4111876e759404834ae7c4375e3f5a635008630ba7af952973150a95e4cf4