[INFO] fetching crate mk20d7-hal 0.1.0...
[INFO] checking mk20d7-hal-0.1.0 against master#b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18 for pr-79470
[INFO] extracting crate mk20d7-hal 0.1.0 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate mk20d7-hal 0.1.0 on toolchain b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mk20d7-hal 0.1.0
[INFO] finished tweaking crates.io crate mk20d7-hal 0.1.0
[INFO] tweaked toml for crates.io crate mk20d7-hal 0.1.0 written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d3e4d6421d55196f86f6b5150c6835e1ef1b1894925101c75ccabf1bed204218
[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" "d3e4d6421d55196f86f6b5150c6835e1ef1b1894925101c75ccabf1bed204218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3e4d6421d55196f86f6b5150c6835e1ef1b1894925101c75ccabf1bed204218", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3e4d6421d55196f86f6b5150c6835e1ef1b1894925101c75ccabf1bed204218", kill_on_drop: false }`
[INFO] [stdout] d3e4d6421d55196f86f6b5150c6835e1ef1b1894925101c75ccabf1bed204218
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a8c5e5c87dbd90065528b8e2602cdc0fb9ac6be5fb6d362c1040d51758bcf77b
[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" "a8c5e5c87dbd90065528b8e2602cdc0fb9ac6be5fb6d362c1040d51758bcf77b", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]    Compiling cortex-m v0.5.10
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]    Compiling mk20d7 v0.1.1
[INFO] [stderr]     Checking aligned v0.2.0
[INFO] [stderr]    Compiling cortex-m v0.4.3
[INFO] [stderr]     Checking untagged-option v0.1.1
[INFO] [stderr]     Checking bare-metal v0.1.3
[INFO] [stderr]     Checking aligned v0.1.2
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]     Checking generic-array v0.13.2
[INFO] [stdout] error[E0740]: unions may not contain fields that need dropping
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/untagged-option-0.1.1/src/lib.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     pub some: T,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: `std::mem::ManuallyDrop` can be used to wrap the type
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/untagged-option-0.1.1/src/lib.rs:53:5
[INFO] [stdout]    |
[INFO] [stdout] 53 |     pub some: T,
[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 E0740`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `untagged-option`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a8c5e5c87dbd90065528b8e2602cdc0fb9ac6be5fb6d362c1040d51758bcf77b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8c5e5c87dbd90065528b8e2602cdc0fb9ac6be5fb6d362c1040d51758bcf77b", kill_on_drop: false }`
[INFO] [stdout] a8c5e5c87dbd90065528b8e2602cdc0fb9ac6be5fb6d362c1040d51758bcf77b