[INFO] crate thruster-async-await 0.7.12 is already in cache
[INFO] testing thruster-async-await-0.7.12 against 1.38.0 for beta-1.39-1
[INFO] extracting crate thruster-async-await 0.7.12 into work/builds/worker-4/source
[INFO] validating manifest of crates.io crate thruster-async-await 0.7.12 on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate thruster-async-await 0.7.12
[INFO] finished tweaking crates.io crate thruster-async-await 0.7.12
[INFO] tweaked toml for crates.io crate thruster-async-await 0.7.12 written to work/builds/worker-4/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 929a27d3a032943e35b0a32389e9cdb56df259e5c78cf9a3c689a0617f4291c3
[INFO] running `"docker" "start" "-a" "929a27d3a032943e35b0a32389e9cdb56df259e5c78cf9a3c689a0617f4291c3"`
[INFO] [stderr]    Compiling either v1.5.3
[INFO] [stderr]    Compiling thruster-core-async-await v0.7.12
[INFO] [stderr]    Compiling futures-core v0.2.1
[INFO] [stderr]    Compiling thruster-core v0.7.12
[INFO] [stderr]    Compiling futures-channel v0.2.1
[INFO] [stderr]    Compiling futures-io v0.2.1
[INFO] [stderr]    Compiling futures-sink v0.2.1
[INFO] [stderr]    Compiling futures-util v0.2.1
[INFO] [stderr]    Compiling thruster-async-await v0.7.12 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(async_await, proc_macro_hygiene)]
[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 `thruster-async-await`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "929a27d3a032943e35b0a32389e9cdb56df259e5c78cf9a3c689a0617f4291c3"`
[INFO] running `"docker" "rm" "-f" "929a27d3a032943e35b0a32389e9cdb56df259e5c78cf9a3c689a0617f4291c3"`
[INFO] [stdout] 929a27d3a032943e35b0a32389e9cdb56df259e5c78cf9a3c689a0617f4291c3