[INFO] updating cached repository silven/actress
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/silven/actress
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/silven/actress" "work/ex/beta-1.38-1/sources/1.37.0/gh/silven/actress"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/silven/actress'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/silven/actress" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silven/actress"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silven/actress'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b91ecabb4ace6f5d06480f292041938e19dee328
[INFO] sha for GitHub repo silven/actress: b91ecabb4ace6f5d06480f292041938e19dee328
[INFO] validating manifest of silven/actress on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of silven/actress on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing silven/actress
[INFO] finished frobbing silven/actress
[INFO] frobbed toml for silven/actress written to work/ex/beta-1.38-1/sources/1.37.0/gh/silven/actress/Cargo.toml
[INFO] started frobbing silven/actress
[INFO] finished frobbing silven/actress
[INFO] frobbed toml for silven/actress written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silven/actress/Cargo.toml
[INFO] crate silven/actress already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing silven/actress against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/silven/actress:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] dba88efdf68b0854129a24b43fd7fd1af7830d0ab01c6850a1a8e7eec5bbebfe
[INFO] running `"docker" "start" "-a" "dba88efdf68b0854129a24b43fd7fd1af7830d0ab01c6850a1a8e7eec5bbebfe"`
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling async-util v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
[INFO] [stderr]    Compiling async-sink v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
[INFO] [stderr]    Compiling arc-waker v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5 (https://github.com/stjepang/crossbeam?branch=raw-parker#e2a7760f)
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling tokio-sync v0.2.0 (https://github.com/tokio-rs/tokio#e7488d98)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/git/checkouts/tokio-377c595163f99a10/e7488d9/tokio-sync/src/lib.rs:10:1
[INFO] [stderr]    |
[INFO] [stderr] 10 | #![feature(async_await)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling tokio-executor v0.2.0 (https://github.com/tokio-rs/tokio#e7488d98)
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `tokio-sync`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "dba88efdf68b0854129a24b43fd7fd1af7830d0ab01c6850a1a8e7eec5bbebfe"`
[INFO] running `"docker" "rm" "-f" "dba88efdf68b0854129a24b43fd7fd1af7830d0ab01c6850a1a8e7eec5bbebfe"`
[INFO] [stdout] dba88efdf68b0854129a24b43fd7fd1af7830d0ab01c6850a1a8e7eec5bbebfe