[INFO] updating cached repository fairingrey/async-proxy
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/fairingrey/async-proxy
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/fairingrey/async-proxy" "work/ex/beta-1.38-1/sources/1.37.0/gh/fairingrey/async-proxy"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/fairingrey/async-proxy'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/fairingrey/async-proxy" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fairingrey/async-proxy"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fairingrey/async-proxy'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d15df5e9a4b1d09ce397c85a7c785eb48a8491ad
[INFO] sha for GitHub repo fairingrey/async-proxy: d15df5e9a4b1d09ce397c85a7c785eb48a8491ad
[INFO] validating manifest of fairingrey/async-proxy 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 fairingrey/async-proxy 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 fairingrey/async-proxy
[INFO] finished frobbing fairingrey/async-proxy
[INFO] frobbed toml for fairingrey/async-proxy written to work/ex/beta-1.38-1/sources/1.37.0/gh/fairingrey/async-proxy/Cargo.toml
[INFO] started frobbing fairingrey/async-proxy
[INFO] finished frobbing fairingrey/async-proxy
[INFO] frobbed toml for fairingrey/async-proxy written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fairingrey/async-proxy/Cargo.toml
[INFO] crate fairingrey/async-proxy 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] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing fairingrey/async-proxy against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/fairingrey/async-proxy:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] b3712f278ca43ffa994a8acdb244caa086dfb1f15d562e98c3a08b828148462e
[INFO] running `"docker" "start" "-a" "b3712f278ca43ffa994a8acdb244caa086dfb1f15d562e98c3a08b828148462e"`
[INFO] [stderr]    Compiling libc v0.2.60
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling spin v0.5.0
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling autocfg v0.1.5
[INFO] [stderr]    Compiling arrayvec v0.4.11
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling log v0.4.7
[INFO] [stderr]    Compiling scopeguard v1.0.0
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling memoffset v0.2.1
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling async-util v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling rustc-demangle v0.1.15
[INFO] [stderr]    Compiling regex v1.1.9
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling arc-waker v0.1.0 (https://github.com/tokio-rs/async#e1b3ba3d)
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling lock_api v0.3.1
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling rand_chacha v0.2.0
[INFO] [stderr]    Compiling regex-syntax v0.6.8
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5 (https://github.com/stjepang/crossbeam?branch=raw-parker#e2a7760f)
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling tracing-core v0.1.2
[INFO] [stderr]    Compiling tokio-futures v0.2.0 (https://github.com/tokio-rs/tokio#d0bb1619)
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling parking_lot_core v0.6.1
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling crossbeam-channel v0.3.8
[INFO] [stderr]    Compiling tokio-executor v0.2.0 (https://github.com/tokio-rs/tokio#d0bb1619)
[INFO] [stderr]    Compiling getrandom v0.1.6
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling tokio-sync v0.2.0 (https://github.com/tokio-rs/tokio#d0bb1619)
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/git/checkouts/tokio-377c595163f99a10/d0bb161/tokio-sync/src/lib.rs:10:1
[INFO] [stderr]    |
[INFO] [stderr] 10 | #![feature(async_await)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling quote v0.6.13
[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" "b3712f278ca43ffa994a8acdb244caa086dfb1f15d562e98c3a08b828148462e"`
[INFO] running `"docker" "rm" "-f" "b3712f278ca43ffa994a8acdb244caa086dfb1f15d562e98c3a08b828148462e"`
[INFO] [stdout] b3712f278ca43ffa994a8acdb244caa086dfb1f15d562e98c3a08b828148462e