[INFO] fetching crate solitaire-core 0.0.1...
[INFO] testing solitaire-core-0.0.1 against beta-2020-06-03 for beta-1.45-1
[INFO] extracting crate solitaire-core 0.0.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate solitaire-core 0.0.1 on toolchain beta-2020-06-03
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate solitaire-core 0.0.1
[INFO] finished tweaking crates.io crate solitaire-core 0.0.1
[INFO] tweaked toml for crates.io crate solitaire-core 0.0.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-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" "+beta-2020-06-03" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 33b6636371e7406edf2c7d4cff9b453713fc9bd26554a9480cf4bc815206ddbf
[INFO] running `"docker" "start" "-a" "33b6636371e7406edf2c7d4cff9b453713fc9bd26554a9480cf4bc815206ddbf"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling syn v1.0.30
[INFO] [stderr]    Compiling serde v1.0.111
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling libz-sys v1.0.25
[INFO] [stderr]    Compiling libgit2-sys v0.9.2
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling url v2.1.1
[INFO] [stderr]    Compiling git2 v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.111
[INFO] [stderr]    Compiling derive_more v0.99.7
[INFO] [stderr]    Compiling toml v0.5.6
[INFO] [stderr]    Compiling serde_json v1.0.53
[INFO] [stderr]    Compiling bincode v1.2.1
[INFO] [stderr]    Compiling uuid v0.8.1
[INFO] [stderr]    Compiling built v0.3.2
[INFO] [stderr]    Compiling solitaire-core v0.0.1 (/opt/rustwide/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(option_expect_none)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(fn_traits)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:3:1
[INFO] [stderr]   |
[INFO] [stderr] 3 | #![feature(unboxed_closures)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `solitaire-core`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "33b6636371e7406edf2c7d4cff9b453713fc9bd26554a9480cf4bc815206ddbf"`
[INFO] running `"docker" "rm" "-f" "33b6636371e7406edf2c7d4cff9b453713fc9bd26554a9480cf4bc815206ddbf"`
[INFO] [stdout] 33b6636371e7406edf2c7d4cff9b453713fc9bd26554a9480cf4bc815206ddbf