[INFO] fetching crate strukt 0.1.0...
[INFO] testing strukt-0.1.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate strukt 0.1.0 into /workspace/builds/worker-40/source
[INFO] validating manifest of crates.io crate strukt 0.1.0 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 strukt 0.1.0
[INFO] finished tweaking crates.io crate strukt 0.1.0
[INFO] tweaked toml for crates.io crate strukt 0.1.0 written to /workspace/builds/worker-40/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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] ab6e08c6c35b9030c800b87bb4676c4ce90a7d337e8f5aedf829c783ad844436
[INFO] running `Command { std: "docker" "start" "-a" "ab6e08c6c35b9030c800b87bb4676c4ce90a7d337e8f5aedf829c783ad844436", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ab6e08c6c35b9030c800b87bb4676c4ce90a7d337e8f5aedf829c783ad844436", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab6e08c6c35b9030c800b87bb4676c4ce90a7d337e8f5aedf829c783ad844436", kill_on_drop: false }`
[INFO] [stdout] ab6e08c6c35b9030c800b87bb4676c4ce90a7d337e8f5aedf829c783ad844436
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-40/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] cf0f9e98e44532f9d683ecbfb7f8d7aff4b51ceea14e39fed01dadb79b49908f
[INFO] running `Command { std: "docker" "start" "-a" "cf0f9e98e44532f9d683ecbfb7f8d7aff4b51ceea14e39fed01dadb79b49908f", kill_on_drop: false }`
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling ucd-util v0.1.8
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]    Compiling strukt v0.1.0 (/opt/rustwide/workdir)
[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(proc_macro)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `proc_macro` has been stable since 1.29.0 and no longer requires an attribute to enable
[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 `strukt` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "cf0f9e98e44532f9d683ecbfb7f8d7aff4b51ceea14e39fed01dadb79b49908f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf0f9e98e44532f9d683ecbfb7f8d7aff4b51ceea14e39fed01dadb79b49908f", kill_on_drop: false }`
[INFO] [stdout] cf0f9e98e44532f9d683ecbfb7f8d7aff4b51ceea14e39fed01dadb79b49908f