[INFO] fetching crate mk20d7-hal 0.1.0...
[INFO] checking mk20d7-hal-0.1.0 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] extracting crate mk20d7-hal 0.1.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate mk20d7-hal 0.1.0 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "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-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded aligned v0.2.0
[INFO] [stderr]   Downloaded cortex-m v0.5.10
[INFO] [stderr]   Downloaded cortex-m-rt v0.5.7
[INFO] [stderr]   Downloaded mk20d7 v0.1.1
[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" "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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", 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] f4b05e37780d0b49e8d318c66fa5a179fd7256e41f7ab7253bbdf534eff13fcd
[INFO] running `Command { std: "docker" "start" "-a" "f4b05e37780d0b49e8d318c66fa5a179fd7256e41f7ab7253bbdf534eff13fcd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f4b05e37780d0b49e8d318c66fa5a179fd7256e41f7ab7253bbdf534eff13fcd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f4b05e37780d0b49e8d318c66fa5a179fd7256e41f7ab7253bbdf534eff13fcd", kill_on_drop: false }`
[INFO] [stdout] f4b05e37780d0b49e8d318c66fa5a179fd7256e41f7ab7253bbdf534eff13fcd
[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" "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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c355072eda26fbd7e18d2a496932d0f3206b317667a04b4c2dd55e7c11c4d3fe
[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" "c355072eda26fbd7e18d2a496932d0f3206b317667a04b4c2dd55e7c11c4d3fe", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.6.3
[INFO] [stderr]     Checking vcell v0.1.2
[INFO] [stderr]    Compiling cortex-m v0.5.10
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]    Compiling mk20d7 v0.1.1
[INFO] [stderr]    Compiling cortex-m v0.4.3
[INFO] [stderr]     Checking aligned v0.2.0
[INFO] [stderr]     Checking bare-metal v0.1.3
[INFO] [stderr]     Checking aligned v0.1.2
[INFO] [stderr]     Checking untagged-option v0.1.1
[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" "c355072eda26fbd7e18d2a496932d0f3206b317667a04b4c2dd55e7c11c4d3fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c355072eda26fbd7e18d2a496932d0f3206b317667a04b4c2dd55e7c11c4d3fe", kill_on_drop: false }`
[INFO] [stdout] c355072eda26fbd7e18d2a496932d0f3206b317667a04b4c2dd55e7c11c4d3fe