[INFO] crate untagged-option 0.2.0 is already in cache
[INFO] testing untagged-option-0.2.0 against 1.45.2 for beta-1.46-1
[INFO] extracting crate untagged-option 0.2.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate untagged-option 0.2.0 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate untagged-option 0.2.0
[INFO] finished tweaking crates.io crate untagged-option 0.2.0
[INFO] tweaked toml for crates.io crate untagged-option 0.2.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c9fca482ab44efd6409bfb5d25e56f6e7ab2cf98698a1a3f2d49327a18d64a45
[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" "c9fca482ab44efd6409bfb5d25e56f6e7ab2cf98698a1a3f2d49327a18d64a45", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c9fca482ab44efd6409bfb5d25e56f6e7ab2cf98698a1a3f2d49327a18d64a45", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c9fca482ab44efd6409bfb5d25e56f6e7ab2cf98698a1a3f2d49327a18d64a45", kill_on_drop: false }`
[INFO] [stdout] c9fca482ab44efd6409bfb5d25e56f6e7ab2cf98698a1a3f2d49327a18d64a45
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", 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] de7913f3f0babf0a513868517bd3fb8f4a617fc45c2d3a10b7a0cb1ab7d252d9
[INFO] running `Command { std: "docker" "start" "-a" "de7913f3f0babf0a513868517bd3fb8f4a617fc45c2d3a10b7a0cb1ab7d252d9", kill_on_drop: false }`
[INFO] [stderr]    Compiling untagged-option v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]   --> src/lib.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(untagged_unions)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `untagged-option`.
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "de7913f3f0babf0a513868517bd3fb8f4a617fc45c2d3a10b7a0cb1ab7d252d9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "de7913f3f0babf0a513868517bd3fb8f4a617fc45c2d3a10b7a0cb1ab7d252d9", kill_on_drop: false }`
[INFO] [stdout] de7913f3f0babf0a513868517bd3fb8f4a617fc45c2d3a10b7a0cb1ab7d252d9