[INFO] crate hazel 0.0.1 is already in cache
[INFO] extracting crate hazel 0.0.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/hazel/0.0.1
[INFO] extracting crate hazel 0.0.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/hazel/0.0.1
[INFO] validating manifest of hazel-0.0.1 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 hazel-0.0.1 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 hazel-0.0.1
[INFO] finished frobbing hazel-0.0.1
[INFO] frobbed toml for hazel-0.0.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/hazel/0.0.1/Cargo.toml
[INFO] started frobbing hazel-0.0.1
[INFO] finished frobbing hazel-0.0.1
[INFO] frobbed toml for hazel-0.0.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/hazel/0.0.1/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] testing hazel-0.0.1 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/hazel/0.0.1:/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] 74b67f5dcfdf6162fa8852c4d65045cc420be48de252e03211fd9ef4c79b1843
[INFO] running `"docker" "start" "-a" "74b67f5dcfdf6162fa8852c4d65045cc420be48de252e03211fd9ef4c79b1843"`
[INFO] [stderr]    Compiling bitboard v0.1.1
[INFO] [stderr] error[E0432]: unresolved import `std::heap`
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/bitboard-0.1.1/src/lib.rs:18:10
[INFO] [stderr]    |
[INFO] [stderr] 18 | use std::heap::{Alloc, Layout, Heap};
[INFO] [stderr]    |          ^^^^ could not find `heap` in `std`
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/bitboard-0.1.1/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(unique, alloc, heap_api, allocator_api, test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0432, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0432`.
[INFO] [stderr] error: Could not compile `bitboard`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "74b67f5dcfdf6162fa8852c4d65045cc420be48de252e03211fd9ef4c79b1843"`
[INFO] running `"docker" "rm" "-f" "74b67f5dcfdf6162fa8852c4d65045cc420be48de252e03211fd9ef4c79b1843"`
[INFO] [stdout] 74b67f5dcfdf6162fa8852c4d65045cc420be48de252e03211fd9ef4c79b1843