[INFO] cloning repository https://github.com/nasa-playground/async-chat
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nasa-playground/async-chat" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnasa-playground%2Fasync-chat", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnasa-playground%2Fasync-chat'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d44d82744742bb42f72ec3d57f27243eabd52e14
[INFO] testing nasa-playground/async-chat against 1.47.0 for beta-1.48-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnasa-playground%2Fasync-chat" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nasa-playground/async-chat on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/nasa-playground/async-chat
[INFO] finished tweaking git repo https://github.com/nasa-playground/async-chat
[INFO] tweaked toml for git repo https://github.com/nasa-playground/async-chat written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/nasa-playground/async-chat already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded async-std v0.99.6
[INFO] [stderr]   Downloaded futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-timer 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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f503913d1827ea269f80d5f07c24352d8c22c07c159d2c89ef13173812edcd0e
[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" "f503913d1827ea269f80d5f07c24352d8c22c07c159d2c89ef13173812edcd0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f503913d1827ea269f80d5f07c24352d8c22c07c159d2c89ef13173812edcd0e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f503913d1827ea269f80d5f07c24352d8c22c07c159d2c89ef13173812edcd0e", kill_on_drop: false }`
[INFO] [stdout] f503913d1827ea269f80d5f07c24352d8c22c07c159d2c89ef13173812edcd0e
[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=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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b051819464a8b6e8463eb93ae482d2cfeb369d79e6c3d5272812ab63a71f17a8
[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" "b051819464a8b6e8463eb93ae482d2cfeb369d79e6c3d5272812ab63a71f17a8", kill_on_drop: false }`
[INFO] [stderr]    Compiling cfg-if v0.1.9
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro2 v1.0.4
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling cc v1.0.45
[INFO] [stderr]    Compiling arrayvec v0.4.11
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling scopeguard v1.0.0
[INFO] [stderr]    Compiling termcolor v1.0.5
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling async-macros v1.0.0
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling async-task v1.0.0
[INFO] [stderr]    Compiling kv-log-macro v1.0.4
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.2
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling getrandom v0.1.12
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling atty v0.2.13
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling mio v0.6.19
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling backtrace v0.3.37
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling proc-macro-hack v0.5.9
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[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 `futures-util-preview`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "b051819464a8b6e8463eb93ae482d2cfeb369d79e6c3d5272812ab63a71f17a8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b051819464a8b6e8463eb93ae482d2cfeb369d79e6c3d5272812ab63a71f17a8", kill_on_drop: false }`
[INFO] [stdout] b051819464a8b6e8463eb93ae482d2cfeb369d79e6c3d5272812ab63a71f17a8
