[INFO] fetching crate trait-union 0.1.4...
[INFO] testing trait-union-0.1.4 against 1.54.0 for beta-1.55-1
[INFO] extracting crate trait-union 0.1.4 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate trait-union 0.1.4 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 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-14/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] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] 2383a199d5fd6d5bdf985c9924633690424d2f62abf130e199e009233cd018a1
[INFO] running `Command { std: "docker" "start" "-a" "2383a199d5fd6d5bdf985c9924633690424d2f62abf130e199e009233cd018a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2383a199d5fd6d5bdf985c9924633690424d2f62abf130e199e009233cd018a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2383a199d5fd6d5bdf985c9924633690424d2f62abf130e199e009233cd018a1", kill_on_drop: false }`
[INFO] [stdout] 2383a199d5fd6d5bdf985c9924633690424d2f62abf130e199e009233cd018a1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] d1319c64071100aab07693c3050b85392c97399dd3780f5c3301016cb789f4a8
[INFO] running `Command { std: "docker" "start" "-a" "d1319c64071100aab07693c3050b85392c97399dd3780f5c3301016cb789f4a8", 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 1.53s
[INFO] running `Command { std: "docker" "inspect" "d1319c64071100aab07693c3050b85392c97399dd3780f5c3301016cb789f4a8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d1319c64071100aab07693c3050b85392c97399dd3780f5c3301016cb789f4a8", kill_on_drop: false }`
[INFO] [stdout] d1319c64071100aab07693c3050b85392c97399dd3780f5c3301016cb789f4a8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] 5f8895f435e6c12a8d8b9ebcb255a91764e8186fb734fd80ca0f917b20c0f41c
[INFO] running `Command { std: "docker" "start" "-a" "5f8895f435e6c12a8d8b9ebcb255a91764e8186fb734fd80ca0f917b20c0f41c", kill_on_drop: false }`
[INFO] [stderr]    Compiling trybuild v1.0.43
[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`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "5f8895f435e6c12a8d8b9ebcb255a91764e8186fb734fd80ca0f917b20c0f41c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5f8895f435e6c12a8d8b9ebcb255a91764e8186fb734fd80ca0f917b20c0f41c", kill_on_drop: false }`
[INFO] [stdout] 5f8895f435e6c12a8d8b9ebcb255a91764e8186fb734fd80ca0f917b20c0f41c
