[INFO] fetching crate const-concat 0.1.0...
[INFO] testing const-concat-0.1.0 against master#5d5ff84130da0d74c6ece368dbe821d8f83fa526 for pr-79296
[INFO] extracting crate const-concat 0.1.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate const-concat 0.1.0 on toolchain 5d5ff84130da0d74c6ece368dbe821d8f83fa526
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate const-concat 0.1.0
[INFO] finished tweaking crates.io crate const-concat 0.1.0
[INFO] tweaked toml for crates.io crate const-concat 0.1.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 025c2e4a630844913fb60810391f7a1f9f7c97f76a03e99cdfe2cf4ea76d9789
[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" "025c2e4a630844913fb60810391f7a1f9f7c97f76a03e99cdfe2cf4ea76d9789", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "025c2e4a630844913fb60810391f7a1f9f7c97f76a03e99cdfe2cf4ea76d9789", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "025c2e4a630844913fb60810391f7a1f9f7c97f76a03e99cdfe2cf4ea76d9789", kill_on_drop: false }`
[INFO] [stdout] 025c2e4a630844913fb60810391f7a1f9f7c97f76a03e99cdfe2cf4ea76d9789
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 323301cbdaf00bfbcc4d075385251ed8ddeb803f4c635abe7fcf5ec8c87afda7
[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" "323301cbdaf00bfbcc4d075385251ed8ddeb803f4c635abe7fcf5ec8c87afda7", kill_on_drop: false }`
[INFO] [stderr]    Compiling const-concat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[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[E0740]: unions may not contain fields that need dropping
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] note: `std::mem::ManuallyDrop` can be used to wrap the type
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0740`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-concat`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "323301cbdaf00bfbcc4d075385251ed8ddeb803f4c635abe7fcf5ec8c87afda7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "323301cbdaf00bfbcc4d075385251ed8ddeb803f4c635abe7fcf5ec8c87afda7", kill_on_drop: false }`
[INFO] [stdout] 323301cbdaf00bfbcc4d075385251ed8ddeb803f4c635abe7fcf5ec8c87afda7