[INFO] crate naja_async_runtime 0.2.1 is already in cache
[INFO] extracting crate naja_async_runtime 0.2.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/naja_async_runtime/0.2.1
[INFO] extracting crate naja_async_runtime 0.2.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/naja_async_runtime/0.2.1
[INFO] validating manifest of naja_async_runtime-0.2.1 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 naja_async_runtime-0.2.1 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 naja_async_runtime-0.2.1
[INFO] finished frobbing naja_async_runtime-0.2.1
[INFO] frobbed toml for naja_async_runtime-0.2.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/naja_async_runtime/0.2.1/Cargo.toml
[INFO] started frobbing naja_async_runtime-0.2.1
[INFO] finished frobbing naja_async_runtime-0.2.1
[INFO] frobbed toml for naja_async_runtime-0.2.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/naja_async_runtime/0.2.1/Cargo.toml
[INFO] crate naja_async_runtime-0.2.1 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 naja_async_runtime-0.2.1 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-1/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/naja_async_runtime/0.2.1:/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] 73ad1fdb9587e9d48864acef41e0fe3da0ef4712f6afd5d6f61bf4ab5dca5548
[INFO] running `"docker" "start" "-a" "73ad1fdb9587e9d48864acef41e0fe3da0ef4712f6afd5d6f61bf4ab5dca5548"`
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling crossbeam-channel v0.3.8
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling backtrace-sys v0.1.30
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling backtrace v0.3.32
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling crossbeam-deque v0.6.3
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]    Compiling parking_lot v0.7.1
[INFO] [stderr]    Compiling crossbeam v0.6.0
[INFO] [stderr]    Compiling once_cell v0.1.8
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.17
[INFO] [stderr]    Compiling juliex v0.3.0-alpha.7
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling naja_async_runtime v0.2.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:257:1
[INFO] [stderr]     |
[INFO] [stderr] 257 | #![ feature( async_await ) ]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[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 `naja_async_runtime`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "73ad1fdb9587e9d48864acef41e0fe3da0ef4712f6afd5d6f61bf4ab5dca5548"`
[INFO] running `"docker" "rm" "-f" "73ad1fdb9587e9d48864acef41e0fe3da0ef4712f6afd5d6f61bf4ab5dca5548"`
[INFO] [stdout] 73ad1fdb9587e9d48864acef41e0fe3da0ef4712f6afd5d6f61bf4ab5dca5548