[INFO] crate eff 0.0.7 is already in cache
[INFO] extracting crate eff 0.0.7 into work/ex/beta-1.38-1/sources/1.37.0/reg/eff/0.0.7
[INFO] extracting crate eff 0.0.7 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/eff/0.0.7
[INFO] validating manifest of eff-0.0.7 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 eff-0.0.7 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 eff-0.0.7
[INFO] finished frobbing eff-0.0.7
[INFO] frobbed toml for eff-0.0.7 written to work/ex/beta-1.38-1/sources/1.37.0/reg/eff/0.0.7/Cargo.toml
[INFO] started frobbing eff-0.0.7
[INFO] finished frobbing eff-0.0.7
[INFO] frobbed toml for eff-0.0.7 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/eff/0.0.7/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 eff-0.0.7 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-1/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/eff/0.0.7:/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] 0cbcfdaea5fd891e360f168658caedba3107343b2bfe55fc9b1a5ff75eed3b18
[INFO] running `"docker" "start" "-a" "0cbcfdaea5fd891e360f168658caedba3107343b2bfe55fc9b1a5ff75eed3b18"`
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling eff-attr v0.0.6
[INFO] [stderr]    Compiling eff v0.0.7 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(generator_trait, never_type, core_intrinsics, extern_types)]
[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 `eff`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0cbcfdaea5fd891e360f168658caedba3107343b2bfe55fc9b1a5ff75eed3b18"`
[INFO] running `"docker" "rm" "-f" "0cbcfdaea5fd891e360f168658caedba3107343b2bfe55fc9b1a5ff75eed3b18"`
[INFO] [stdout] 0cbcfdaea5fd891e360f168658caedba3107343b2bfe55fc9b1a5ff75eed3b18