[INFO] crate mason 0.0.0 is already in cache
[INFO] testing mason-0.0.0 against 1.45.2 for beta-1.46-1
[INFO] extracting crate mason 0.0.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate mason 0.0.0 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mason 0.0.0
[INFO] finished tweaking crates.io crate mason 0.0.0
[INFO] tweaked toml for crates.io crate mason 0.0.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] da5e7a48fffc49302e42c29865ab5423f7f4c654b31cbc922672eeebb6c1438a
[INFO] running `Command { std: "docker" "start" "-a" "da5e7a48fffc49302e42c29865ab5423f7f4c654b31cbc922672eeebb6c1438a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "da5e7a48fffc49302e42c29865ab5423f7f4c654b31cbc922672eeebb6c1438a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da5e7a48fffc49302e42c29865ab5423f7f4c654b31cbc922672eeebb6c1438a", kill_on_drop: false }`
[INFO] [stdout] da5e7a48fffc49302e42c29865ab5423f7f4c654b31cbc922672eeebb6c1438a
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8c838ab85b870a3dfb9595eb2539a581d45989faf1473bd02efbf3bbaa2af87
[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" "b8c838ab85b870a3dfb9595eb2539a581d45989faf1473bd02efbf3bbaa2af87", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures v0.1.29
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling pin-utils v0.1.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling syn v1.0.36
[INFO] [stderr]    Compiling async-datagram v3.0.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling async-ready v3.0.0
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling quick-error v1.2.3
[INFO] [stderr]    Compiling termcolor v1.1.0
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling lock_api v0.3.4
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.34
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling smallvec v0.6.13
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling mio v0.6.22
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling mio-uds v0.6.8
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling crossbeam-queue v0.2.3
[INFO] [stderr]    Compiling crossbeam-channel v0.4.3
[INFO] [stderr]    Compiling crossbeam-deque v0.7.3
[INFO] [stderr]    Compiling crossbeam v0.7.3
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-timer v0.3.0
[INFO] [stderr]    Compiling runtime-raw v0.3.0-alpha.5
[INFO] [stderr]    Compiling romio v0.3.0-alpha.10
[INFO] [stderr]    Compiling juliex v0.3.0-alpha.8
[INFO] [stderr]    Compiling runtime-native v0.3.0-alpha.6
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling runtime-attributes v0.3.0-alpha.6
[INFO] [stderr]    Compiling runtime v0.3.0-alpha.4
[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/runtime-0.3.0-alpha.4/src/lib.rs:88:1
[INFO] [stdout]    |
[INFO] [stdout] 88 | #![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 `runtime`.
[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" "b8c838ab85b870a3dfb9595eb2539a581d45989faf1473bd02efbf3bbaa2af87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8c838ab85b870a3dfb9595eb2539a581d45989faf1473bd02efbf3bbaa2af87", kill_on_drop: false }`
[INFO] [stdout] b8c838ab85b870a3dfb9595eb2539a581d45989faf1473bd02efbf3bbaa2af87