[INFO] fetching crate zerogc-derive 0.2.0-alpha.6...
[INFO] testing zerogc-derive-0.2.0-alpha.6 against 1.59.0 for beta-1.60-1
[INFO] extracting crate zerogc-derive 0.2.0-alpha.6 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate zerogc-derive 0.2.0-alpha.6 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate zerogc-derive 0.2.0-alpha.6
[INFO] finished tweaking crates.io crate zerogc-derive 0.2.0-alpha.6
[INFO] tweaked toml for crates.io crate zerogc-derive 0.2.0-alpha.6 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "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" "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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 693d346cf4cfce38d57ffec14d85816edf1969fbf1634f505c310e8bc2201437
[INFO] running `Command { std: "docker" "start" "-a" "693d346cf4cfce38d57ffec14d85816edf1969fbf1634f505c310e8bc2201437", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "693d346cf4cfce38d57ffec14d85816edf1969fbf1634f505c310e8bc2201437", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "693d346cf4cfce38d57ffec14d85816edf1969fbf1634f505c310e8bc2201437", kill_on_drop: false }`
[INFO] [stdout] 693d346cf4cfce38d57ffec14d85816edf1969fbf1634f505c310e8bc2201437
[INFO] running `Command { std: "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" "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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5f9a12a20fbc00e3b9d4c34802c39264b9d4f3b06419a74e3ce1a03642469229
[INFO] running `Command { std: "docker" "start" "-a" "5f9a12a20fbc00e3b9d4c34802c39264b9d4f3b06419a74e3ce1a03642469229", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling libc v0.2.119
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling once_cell v1.9.0
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]    Compiling unicode-segmentation v1.9.0
[INFO] [stderr]    Compiling strsim v0.10.0
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling ahash v0.7.6
[INFO] [stderr]    Compiling indexmap v1.8.0
[INFO] [stderr]    Compiling itertools v0.10.3
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling getrandom v0.2.5
[INFO] [stderr]    Compiling darling_core v0.13.1
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling proc-macro-kwargs-derive v0.1.5
[INFO] [stderr]    Compiling darling_macro v0.13.1
[INFO] [stderr]    Compiling darling v0.13.1
[INFO] [stderr]    Compiling hashbrown v0.11.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/hashbrown-0.11.2/src/lib.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     feature(
[INFO] [stdout] 16 | |         test,
[INFO] [stdout] 17 | |         core_intrinsics,
[INFO] [stdout] 18 | |         dropck_eyepatch,
[INFO] [stdout] ...  |
[INFO] [stdout] 24 | |         maybe_uninit_array_assume_init
[INFO] [stdout] 25 | |     )
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hashbrown` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "5f9a12a20fbc00e3b9d4c34802c39264b9d4f3b06419a74e3ce1a03642469229", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f9a12a20fbc00e3b9d4c34802c39264b9d4f3b06419a74e3ce1a03642469229", kill_on_drop: false }`
[INFO] [stdout] 5f9a12a20fbc00e3b9d4c34802c39264b9d4f3b06419a74e3ce1a03642469229