[INFO] crate effect-monad 0.3.1 is already in cache
[INFO] extracting crate effect-monad 0.3.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/effect-monad/0.3.1
[INFO] extracting crate effect-monad 0.3.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/effect-monad/0.3.1
[INFO] validating manifest of effect-monad-0.3.1 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 effect-monad-0.3.1 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 effect-monad-0.3.1
[INFO] removed 1 missing examples
[INFO] finished frobbing effect-monad-0.3.1
[INFO] frobbed toml for effect-monad-0.3.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/effect-monad/0.3.1/Cargo.toml
[INFO] started frobbing effect-monad-0.3.1
[INFO] removed 1 missing examples
[INFO] finished frobbing effect-monad-0.3.1
[INFO] frobbed toml for effect-monad-0.3.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/effect-monad/0.3.1/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing effect-monad-0.3.1 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-0/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/effect-monad/0.3.1:/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] ede76a1d7268c831f8bb8fefc09279887a02e1903dcc37abd35961b493341e36
[INFO] running `"docker" "start" "-a" "ede76a1d7268c831f8bb8fefc09279887a02e1903dcc37abd35961b493341e36"`
[INFO] [stderr] warning: An explicit [[example]] section is specified in Cargo.toml which currently
[INFO] [stderr] disables Cargo from automatically inferring other example targets.
[INFO] [stderr] This inference behavior will change in the Rust 2018 edition and the following
[INFO] [stderr] files will be included as a example target:
[INFO] [stderr] 
[INFO] [stderr] * /opt/crater/workdir/examples/hello_goodbye.rs
[INFO] [stderr] 
[INFO] [stderr] This is likely to break cargo build or cargo test as these files may not be
[INFO] [stderr] ready to be compiled as a example target today. You can future-proof yourself
[INFO] [stderr] and disable this warning by adding `autoexamples = false` to your [package]
[INFO] [stderr] section. You may also move the files to a location where Cargo would not
[INFO] [stderr] automatically infer them to be a target, such as in subfolders.
[INFO] [stderr] 
[INFO] [stderr] For more information on this warning you can consult
[INFO] [stderr] https://github.com/rust-lang/cargo/issues/5330
[INFO] [stderr]    Compiling effect-monad v0.3.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![feature(fn_traits, unboxed_closures)]
[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 `effect-monad`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "ede76a1d7268c831f8bb8fefc09279887a02e1903dcc37abd35961b493341e36"`
[INFO] running `"docker" "rm" "-f" "ede76a1d7268c831f8bb8fefc09279887a02e1903dcc37abd35961b493341e36"`
[INFO] [stdout] ede76a1d7268c831f8bb8fefc09279887a02e1903dcc37abd35961b493341e36