[INFO] fetching crate trait-union 0.1.4...
[INFO] testing trait-union-0.1.4 against 1.59.0 for beta-1.60-1
[INFO] extracting crate trait-union 0.1.4 into /workspace/builds/worker-21/source
[INFO] validating manifest of crates.io crate trait-union 0.1.4 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 trait-union 0.1.4
[INFO] finished tweaking crates.io crate trait-union 0.1.4
[INFO] tweaked toml for crates.io crate trait-union 0.1.4 written to /workspace/builds/worker-21/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/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] 49b40c6388f9d082bcfa350f85fac9dd6877f91130f9b65a36536d1c0ef64467
[INFO] running `Command { std: "docker" "start" "-a" "49b40c6388f9d082bcfa350f85fac9dd6877f91130f9b65a36536d1c0ef64467", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "49b40c6388f9d082bcfa350f85fac9dd6877f91130f9b65a36536d1c0ef64467", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "49b40c6388f9d082bcfa350f85fac9dd6877f91130f9b65a36536d1c0ef64467", kill_on_drop: false }`
[INFO] [stdout] 49b40c6388f9d082bcfa350f85fac9dd6877f91130f9b65a36536d1c0ef64467
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/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] 62b91dbab9815b9819e262817b0d03cef7467d4b195ffe78e29388ecdb738256
[INFO] running `Command { std: "docker" "start" "-a" "62b91dbab9815b9819e262817b0d03cef7467d4b195ffe78e29388ecdb738256", 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] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling trait-union-proc v0.1.4
[INFO] [stderr]    Compiling trait-union v0.1.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.17s
[INFO] running `Command { std: "docker" "inspect" "62b91dbab9815b9819e262817b0d03cef7467d4b195ffe78e29388ecdb738256", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "62b91dbab9815b9819e262817b0d03cef7467d4b195ffe78e29388ecdb738256", kill_on_drop: false }`
[INFO] [stdout] 62b91dbab9815b9819e262817b0d03cef7467d4b195ffe78e29388ecdb738256
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-21/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" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 338d138a6fbe350e5f0de189d35f77b8ed044cc8274cfb5ce26e3218d5ee1e49
[INFO] running `Command { std: "docker" "start" "-a" "338d138a6fbe350e5f0de189d35f77b8ed044cc8274cfb5ce26e3218d5ee1e49", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]    Compiling ryu v1.0.9
[INFO] [stderr]    Compiling itoa v1.0.1
[INFO] [stderr]    Compiling trybuild v1.0.56
[INFO] [stderr]    Compiling once_cell v1.9.0
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling glob v0.3.0
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling toml v0.5.8
[INFO] [stderr]    Compiling trait-union v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(test, feature(untagged_unions))]
[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 `trait-union` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "338d138a6fbe350e5f0de189d35f77b8ed044cc8274cfb5ce26e3218d5ee1e49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "338d138a6fbe350e5f0de189d35f77b8ed044cc8274cfb5ce26e3218d5ee1e49", kill_on_drop: false }`
[INFO] [stdout] 338d138a6fbe350e5f0de189d35f77b8ed044cc8274cfb5ce26e3218d5ee1e49