[INFO] fetching crate solitaire-core 0.0.1...
[INFO] testing solitaire-core-0.0.1 against 1.54.0 for beta-1.55-1
[INFO] extracting crate solitaire-core 0.0.1 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate solitaire-core 0.0.1 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[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-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d2b99d6386ea0f76f8a3bcaae919df64a685da55d609de6869e39cff73e46dfc
[INFO] running `Command { std: "docker" "start" "-a" "d2b99d6386ea0f76f8a3bcaae919df64a685da55d609de6869e39cff73e46dfc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d2b99d6386ea0f76f8a3bcaae919df64a685da55d609de6869e39cff73e46dfc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d2b99d6386ea0f76f8a3bcaae919df64a685da55d609de6869e39cff73e46dfc", kill_on_drop: false }`
[INFO] [stdout] d2b99d6386ea0f76f8a3bcaae919df64a685da55d609de6869e39cff73e46dfc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "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" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 501304b3290c3c7d389f0d33353325250571dd65f9ebc6f0db1e5be51affa58c
[INFO] running `Command { std: "docker" "start" "-a" "501304b3290c3c7d389f0d33353325250571dd65f9ebc6f0db1e5be51affa58c", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling jobserver v0.1.23
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling cc v1.0.69
[INFO] [stderr]    Compiling libz-sys v1.1.3
[INFO] [stderr]    Compiling libgit2-sys v0.9.2
[INFO] [stderr]    Compiling git2 v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.127
[INFO] [stderr]    Compiling derive_more v0.99.16
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]    Compiling toml v0.5.8
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling bincode v1.3.3
[INFO] [stderr]    Compiling uuid v0.8.2
[INFO] [stderr]    Compiling built v0.3.2
[INFO] [stderr]    Compiling solitaire-core v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(option_expect_none)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(fn_traits)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(unboxed_closures)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `solitaire-core`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "501304b3290c3c7d389f0d33353325250571dd65f9ebc6f0db1e5be51affa58c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "501304b3290c3c7d389f0d33353325250571dd65f9ebc6f0db1e5be51affa58c", kill_on_drop: false }`
[INFO] [stdout] 501304b3290c3c7d389f0d33353325250571dd65f9ebc6f0db1e5be51affa58c
