[INFO] fetching crate rabbithole 0.3.1...
[INFO] testing rabbithole-0.3.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate rabbithole 0.3.1 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate rabbithole 0.3.1 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 rabbithole 0.3.1
[INFO] finished tweaking crates.io crate rabbithole 0.3.1
[INFO] tweaked toml for crates.io crate rabbithole 0.3.1 written to /workspace/builds/worker-8/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] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] 865d1bb275385cf32be719eafe0bcedc7bb3abcf1f93a305a4f9d0d44418823e
[INFO] running `Command { std: "docker" "start" "-a" "865d1bb275385cf32be719eafe0bcedc7bb3abcf1f93a305a4f9d0d44418823e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "865d1bb275385cf32be719eafe0bcedc7bb3abcf1f93a305a4f9d0d44418823e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "865d1bb275385cf32be719eafe0bcedc7bb3abcf1f93a305a4f9d0d44418823e", kill_on_drop: false }`
[INFO] [stdout] 865d1bb275385cf32be719eafe0bcedc7bb3abcf1f93a305a4f9d0d44418823e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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] 63642a6771c45bfe568b68e470e687a8602d684b9103fe228b9063d647dc41b9
[INFO] running `Command { std: "docker" "start" "-a" "63642a6771c45bfe568b68e470e687a8602d684b9103fe228b9063d647dc41b9", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling frunk_core v0.3.2
[INFO] [stderr]    Compiling strum v0.16.0
[INFO] [stderr]    Compiling pest v2.0.2
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling syn v0.14.9
[INFO] [stderr]    Compiling url v2.1.1
[INFO] [stderr]    Compiling http v0.1.21
[INFO] [stderr]    Compiling pest_meta v2.0.3
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling pest_generator v2.0.0
[INFO] [stderr]    Compiling frunk_proc_macro_helpers v0.0.5
[INFO] [stderr]    Compiling pest_derive v2.0.1
[INFO] [stderr]    Compiling frunk_proc_macros_impl v0.0.5
[INFO] [stderr]    Compiling frunk_derives v0.3.2
[INFO] [stderr]    Compiling frunk_proc_macros v0.0.5
[INFO] [stderr]    Compiling frunk v0.3.2
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]    Compiling thiserror-impl v1.0.29
[INFO] [stderr]    Compiling strum_macros v0.16.0
[INFO] [stderr]    Compiling async-trait v0.1.51
[INFO] [stderr]    Compiling thiserror v1.0.29
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling serde_json v1.0.67
[INFO] [stderr]    Compiling uuid v0.8.2
[INFO] [stderr]    Compiling rsql-rs v0.2.0
[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/rsql-rs-0.2.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(backtrace)]
[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 `rsql-rs` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "63642a6771c45bfe568b68e470e687a8602d684b9103fe228b9063d647dc41b9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63642a6771c45bfe568b68e470e687a8602d684b9103fe228b9063d647dc41b9", kill_on_drop: false }`
[INFO] [stdout] 63642a6771c45bfe568b68e470e687a8602d684b9103fe228b9063d647dc41b9