[INFO] fetching crate trait-union 0.1.4...
[INFO] testing trait-union-0.1.4 against 1.47.0 for beta-1.48-1
[INFO] extracting crate trait-union 0.1.4 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate trait-union 0.1.4 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", 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-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4f4dbd84e71bce13c520e05925ef21267634c344088a9123c2e4450c4abef333
[INFO] running `Command { std: "docker" "start" "-a" "4f4dbd84e71bce13c520e05925ef21267634c344088a9123c2e4450c4abef333", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4f4dbd84e71bce13c520e05925ef21267634c344088a9123c2e4450c4abef333", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f4dbd84e71bce13c520e05925ef21267634c344088a9123c2e4450c4abef333", kill_on_drop: false }`
[INFO] [stdout] 4f4dbd84e71bce13c520e05925ef21267634c344088a9123c2e4450c4abef333
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9d649e163816fda962986be69d259b517b5ed55d561751439174913b92126ebc
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "9d649e163816fda962986be69d259b517b5ed55d561751439174913b92126ebc", kill_on_drop: false }`
[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 1.64s
[INFO] running `Command { std: "docker" "inspect" "9d649e163816fda962986be69d259b517b5ed55d561751439174913b92126ebc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9d649e163816fda962986be69d259b517b5ed55d561751439174913b92126ebc", kill_on_drop: false }`
[INFO] [stdout] 9d649e163816fda962986be69d259b517b5ed55d561751439174913b92126ebc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4888f859aac4eaff77a04d2715212d17dbb9a8b9984f821f048d005527dcae36
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "4888f859aac4eaff77a04d2715212d17dbb9a8b9984f821f048d005527dcae36", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_json v1.0.59
[INFO] [stderr]    Compiling trybuild v1.0.35
[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`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4888f859aac4eaff77a04d2715212d17dbb9a8b9984f821f048d005527dcae36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4888f859aac4eaff77a04d2715212d17dbb9a8b9984f821f048d005527dcae36", kill_on_drop: false }`
[INFO] [stdout] 4888f859aac4eaff77a04d2715212d17dbb9a8b9984f821f048d005527dcae36
