[INFO] fetching crate udp_server 0.3.6...
[INFO] testing udp_server-0.3.6 against 1.49.0 for beta-1.50-1
[INFO] extracting crate udp_server 0.3.6 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate udp_server 0.3.6 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate udp_server 0.3.6
[INFO] finished tweaking crates.io crate udp_server 0.3.6
[INFO] tweaked toml for crates.io crate udp_server 0.3.6 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 882e5c43f9277733cff33db90403ab65a7b8c6fe139544eb78f0f3a66b84e09f
[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" "882e5c43f9277733cff33db90403ab65a7b8c6fe139544eb78f0f3a66b84e09f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "882e5c43f9277733cff33db90403ab65a7b8c6fe139544eb78f0f3a66b84e09f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "882e5c43f9277733cff33db90403ab65a7b8c6fe139544eb78f0f3a66b84e09f", kill_on_drop: false }`
[INFO] [stdout] 882e5c43f9277733cff33db90403ab65a7b8c6fe139544eb78f0f3a66b84e09f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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=warn" "-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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9353e2e70df7d1066cc2e6c72ea215412ee9a0fad06e08d336221dc26e17e441
[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" "9353e2e70df7d1066cc2e6c72ea215412ee9a0fad06e08d336221dc26e17e441", kill_on_drop: false }`
[INFO] [stderr]    Compiling tokio v0.2.24
[INFO] [stderr]    Compiling futures-util v0.3.8
[INFO] [stderr]    Compiling futures-executor v0.3.8
[INFO] [stderr]    Compiling futures v0.3.8
[INFO] [stderr]    Compiling udp_server v0.3.6 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 13.34s
[INFO] running `Command { std: "docker" "inspect" "9353e2e70df7d1066cc2e6c72ea215412ee9a0fad06e08d336221dc26e17e441", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9353e2e70df7d1066cc2e6c72ea215412ee9a0fad06e08d336221dc26e17e441", kill_on_drop: false }`
[INFO] [stdout] 9353e2e70df7d1066cc2e6c72ea215412ee9a0fad06e08d336221dc26e17e441
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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=warn" "-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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b1227e615cce2d6e68f94223c457c61c9327f07ab7f34d19bf5225a3f0c95c74
[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" "b1227e615cce2d6e68f94223c457c61c9327f07ab7f34d19bf5225a3f0c95c74", kill_on_drop: false }`
[INFO] [stderr]    Compiling udp_server v0.3.6 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> tests/udp.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(async_closure)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `udp_server`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "b1227e615cce2d6e68f94223c457c61c9327f07ab7f34d19bf5225a3f0c95c74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b1227e615cce2d6e68f94223c457c61c9327f07ab7f34d19bf5225a3f0c95c74", kill_on_drop: false }`
[INFO] [stdout] b1227e615cce2d6e68f94223c457c61c9327f07ab7f34d19bf5225a3f0c95c74