[INFO] fetching crate rpa_enum 0.1.6...
[INFO] testing rpa_enum-0.1.6 against 1.90.0 for beta-1.91-3
[INFO] extracting crate rpa_enum 0.1.6 into /workspace/builds/worker-3-tc1/source
[INFO] started tweaking crates.io crate rpa_enum 0.1.6
[INFO] finished tweaking crates.io crate rpa_enum 0.1.6
[INFO] tweaked toml for crates.io crate rpa_enum 0.1.6 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate rpa_enum 0.1.6 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 11 packages to latest compatible versions
[INFO] [stderr]       Adding syn v1.0.109 (available: v2.0.106)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 93f90cbc306ade8a7caaca4292950402d0998bd580013d0a426050a5e07f96e1
[INFO] running `Command { std: "docker" "start" "-a" "93f90cbc306ade8a7caaca4292950402d0998bd580013d0a426050a5e07f96e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "93f90cbc306ade8a7caaca4292950402d0998bd580013d0a426050a5e07f96e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "93f90cbc306ade8a7caaca4292950402d0998bd580013d0a426050a5e07f96e1", kill_on_drop: false }`
[INFO] [stdout] 93f90cbc306ade8a7caaca4292950402d0998bd580013d0a426050a5e07f96e1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6713788b11bb27256ca8214fae3c4f9227a7000fe3924340b05c5ba9bf265e85
[INFO] running `Command { std: "docker" "start" "-a" "6713788b11bb27256ca8214fae3c4f9227a7000fe3924340b05c5ba9bf265e85", kill_on_drop: false }`
[INFO] [stderr]    Compiling Inflector v0.11.4
[INFO] [stderr]    Compiling rpa_enum v0.1.6 (/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_hygiene, decl_macro)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rpa_enum` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "6713788b11bb27256ca8214fae3c4f9227a7000fe3924340b05c5ba9bf265e85", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6713788b11bb27256ca8214fae3c4f9227a7000fe3924340b05c5ba9bf265e85", kill_on_drop: false }`
[INFO] [stdout] 6713788b11bb27256ca8214fae3c4f9227a7000fe3924340b05c5ba9bf265e85