[INFO] fetching crate second-stack 0.2.1...
[INFO] testing second-stack-0.2.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate second-stack 0.2.1 into /workspace/builds/worker-80/source
[INFO] validating manifest of crates.io crate second-stack 0.2.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate second-stack 0.2.1
[INFO] finished tweaking crates.io crate second-stack 0.2.1
[INFO] tweaked toml for crates.io crate second-stack 0.2.1 written to /workspace/builds/worker-80/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded testdrop v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1bdaf6c65e8ac4a85737a91e77f300bf034cde138245d12df329887433c7bec0
[INFO] running `Command { std: "docker" "start" "-a" "1bdaf6c65e8ac4a85737a91e77f300bf034cde138245d12df329887433c7bec0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1bdaf6c65e8ac4a85737a91e77f300bf034cde138245d12df329887433c7bec0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1bdaf6c65e8ac4a85737a91e77f300bf034cde138245d12df329887433c7bec0", kill_on_drop: false }`
[INFO] [stdout] 1bdaf6c65e8ac4a85737a91e77f300bf034cde138245d12df329887433c7bec0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-80/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f40962bfa4f79b961454ea2c28c4a0f103459be4070c2fd51b236a8e8571d28e
[INFO] running `Command { std: "docker" "start" "-a" "f40962bfa4f79b961454ea2c28c4a0f103459be4070c2fd51b236a8e8571d28e", kill_on_drop: false }`
[INFO] [stderr]    Compiling second-stack v0.2.1 (/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(allocator_api, alloc_layout_extra, ptr_offset_from)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `alloc` found for struct `std::alloc::Global` in the current scope
[INFO] [stdout]    --> src/lib.rs:108:33
[INFO] [stdout]     |
[INFO] [stdout] 108 |             let bottom = Global.alloc(layout).unwrap().as_ptr(); // TODO: There may be mitigation, like not doubling in size.
[INFO] [stdout]     |                                 ^^^^^ method not found in `std::alloc::Global`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `dealloc` found for struct `std::alloc::Global` in the current scope
[INFO] [stdout]    --> src/lib.rs:126:24
[INFO] [stdout]     |
[INFO] [stdout] 126 |                 Global.dealloc(bottom, layout);
[INFO] [stdout]     |                        ^^^^^^^ method not found in `std::alloc::Global`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `second-stack` due to 4 previous errors
[INFO] running `Command { std: "docker" "inspect" "f40962bfa4f79b961454ea2c28c4a0f103459be4070c2fd51b236a8e8571d28e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f40962bfa4f79b961454ea2c28c4a0f103459be4070c2fd51b236a8e8571d28e", kill_on_drop: false }`
[INFO] [stdout] f40962bfa4f79b961454ea2c28c4a0f103459be4070c2fd51b236a8e8571d28e