[INFO] fetching crate trait-union 0.1.4...
[INFO] testing trait-union-0.1.4 against 1.49.0 for beta-1.50-1
[INFO] extracting crate trait-union 0.1.4 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate trait-union 0.1.4 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "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-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--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-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f385d0dd9ff206c07c98b9e93b619834cc9f10139fa3c2d8eb0be75b161bc673
[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" "f385d0dd9ff206c07c98b9e93b619834cc9f10139fa3c2d8eb0be75b161bc673", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f385d0dd9ff206c07c98b9e93b619834cc9f10139fa3c2d8eb0be75b161bc673", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f385d0dd9ff206c07c98b9e93b619834cc9f10139fa3c2d8eb0be75b161bc673", kill_on_drop: false }`
[INFO] [stdout] f385d0dd9ff206c07c98b9e93b619834cc9f10139fa3c2d8eb0be75b161bc673
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 39ca7a561cffebf7f2fd3d1ad3e09477ea35b2ef0e227299a8a628bb382c4f4c
[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" "39ca7a561cffebf7f2fd3d1ad3e09477ea35b2ef0e227299a8a628bb382c4f4c", 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 1.83s
[INFO] running `Command { std: "docker" "inspect" "39ca7a561cffebf7f2fd3d1ad3e09477ea35b2ef0e227299a8a628bb382c4f4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39ca7a561cffebf7f2fd3d1ad3e09477ea35b2ef0e227299a8a628bb382c4f4c", kill_on_drop: false }`
[INFO] [stdout] 39ca7a561cffebf7f2fd3d1ad3e09477ea35b2ef0e227299a8a628bb382c4f4c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--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] dfa56c13cf9bcf4995c1546d2f2e6f86f7690b2eddc1ade51355f206b82f5bfa
[INFO] running `Command { std: "docker" "start" "-a" "dfa56c13cf9bcf4995c1546d2f2e6f86f7690b2eddc1ade51355f206b82f5bfa", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling toml v0.5.8
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]    Compiling trybuild v1.0.38
[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" "dfa56c13cf9bcf4995c1546d2f2e6f86f7690b2eddc1ade51355f206b82f5bfa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dfa56c13cf9bcf4995c1546d2f2e6f86f7690b2eddc1ade51355f206b82f5bfa", kill_on_drop: false }`
[INFO] [stdout] dfa56c13cf9bcf4995c1546d2f2e6f86f7690b2eddc1ade51355f206b82f5bfa