[INFO] fetching crate uwl 0.6.0...
[INFO] testing uwl-0.6.0 against 1.54.0 for beta-1.55-1
[INFO] extracting crate uwl 0.6.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate uwl 0.6.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate uwl 0.6.0
[INFO] finished tweaking crates.io crate uwl 0.6.0
[INFO] tweaked toml for crates.io crate uwl 0.6.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4a72028efaab8c178c4700d3447da3fcf7a170abfc568b893abad8b5879735b4
[INFO] running `Command { std: "docker" "start" "-a" "4a72028efaab8c178c4700d3447da3fcf7a170abfc568b893abad8b5879735b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a72028efaab8c178c4700d3447da3fcf7a170abfc568b893abad8b5879735b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a72028efaab8c178c4700d3447da3fcf7a170abfc568b893abad8b5879735b4", kill_on_drop: false }`
[INFO] [stdout] 4a72028efaab8c178c4700d3447da3fcf7a170abfc568b893abad8b5879735b4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4fa008f7e91e997c6afd4c283b0698ffccfbe3be6451f730a64f37f73f8c4a87
[INFO] running `Command { std: "docker" "start" "-a" "4fa008f7e91e997c6afd4c283b0698ffccfbe3be6451f730a64f37f73f8c4a87", kill_on_drop: false }`
[INFO] [stderr]    Compiling uwl v0.6.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.18s
[INFO] running `Command { std: "docker" "inspect" "4fa008f7e91e997c6afd4c283b0698ffccfbe3be6451f730a64f37f73f8c4a87", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4fa008f7e91e997c6afd4c283b0698ffccfbe3be6451f730a64f37f73f8c4a87", kill_on_drop: false }`
[INFO] [stdout] 4fa008f7e91e997c6afd4c283b0698ffccfbe3be6451f730a64f37f73f8c4a87
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 50501a50a5b54a4dc1e4471cc53dfbfc60c3a5ffdc28211e672ab6cf1ed4876f
[INFO] running `Command { std: "docker" "start" "-a" "50501a50a5b54a4dc1e4471cc53dfbfc60c3a5ffdc28211e672ab6cf1ed4876f", kill_on_drop: false }`
[INFO] [stderr]    Compiling uwl v0.6.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:90:19
[INFO] [stdout]    |
[INFO] [stdout] 90 | #![cfg_attr(test, feature(test))]
[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 `uwl`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "50501a50a5b54a4dc1e4471cc53dfbfc60c3a5ffdc28211e672ab6cf1ed4876f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "50501a50a5b54a4dc1e4471cc53dfbfc60c3a5ffdc28211e672ab6cf1ed4876f", kill_on_drop: false }`
[INFO] [stdout] 50501a50a5b54a4dc1e4471cc53dfbfc60c3a5ffdc28211e672ab6cf1ed4876f
