[INFO] fetching crate atsamd21-hal 0.3.1...
[INFO] checking atsamd21-hal-0.3.1 against try#99a443d6903f71d521237d8acb5a3016b534d17b for pr-83354
[INFO] extracting crate atsamd21-hal 0.3.1 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate atsamd21-hal 0.3.1 on toolchain 99a443d6903f71d521237d8acb5a3016b534d17b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99a443d6903f71d521237d8acb5a3016b534d17b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate atsamd21-hal 0.3.1
[INFO] finished tweaking crates.io crate atsamd21-hal 0.3.1
[INFO] tweaked toml for crates.io crate atsamd21-hal 0.3.1 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99a443d6903f71d521237d8acb5a3016b534d17b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99a443d6903f71d521237d8acb5a3016b534d17b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded cortex-m v0.4.3
[INFO] [stderr]   Downloaded cortex-m v0.5.11
[INFO] [stderr]   Downloaded untagged-option v0.1.1
[INFO] [stderr]   Downloaded cortex-m-rtfm-macros v0.3.2
[INFO] [stderr]   Downloaded aligned v0.1.2
[INFO] [stderr]   Downloaded cortex-m-semihosting v0.2.1
[INFO] [stderr]   Downloaded bare-metal v0.1.3
[INFO] [stderr]   Downloaded rtfm-syntax v0.3.4
[INFO] [stderr]   Downloaded panic_rtt v0.1.0
[INFO] [stderr]   Downloaded panic-abort v0.3.2
[INFO] [stderr]   Downloaded rtfm-core v0.2.0
[INFO] [stderr]   Downloaded cortex-m-rtfm v0.3.4
[INFO] [stderr]   Downloaded atsamd21e18a v0.4.0
[INFO] [stderr]   Downloaded atsamd21g18a v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+99a443d6903f71d521237d8acb5a3016b534d17b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ab82639fb83cd3ec24c3f9d0c78f066a4bbecbe97a5508f137758bc0eeee4ba1
[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" "ab82639fb83cd3ec24c3f9d0c78f066a4bbecbe97a5508f137758bc0eeee4ba1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ab82639fb83cd3ec24c3f9d0c78f066a4bbecbe97a5508f137758bc0eeee4ba1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab82639fb83cd3ec24c3f9d0c78f066a4bbecbe97a5508f137758bc0eeee4ba1", kill_on_drop: false }`
[INFO] [stdout] ab82639fb83cd3ec24c3f9d0c78f066a4bbecbe97a5508f137758bc0eeee4ba1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+99a443d6903f71d521237d8acb5a3016b534d17b" "check" "--frozen" "--all" "--all-targets" "--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] 8c145de1adafe25de26882e300a312320a0e606466f04ab2200e2387a19f08de
[INFO] running `Command { std: "docker" "start" "-a" "8c145de1adafe25de26882e300a312320a0e606466f04ab2200e2387a19f08de", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling typenum v1.13.0
[INFO] [stderr]    Compiling cortex-m v0.7.2
[INFO] [stderr]     Checking vcell v0.1.3
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]    Compiling syn v1.0.65
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]    Compiling libc v0.2.91
[INFO] [stderr]    Compiling gimli v0.23.0
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling rustc-demangle v0.1.18
[INFO] [stderr]    Compiling object v0.23.0
[INFO] [stderr]    Compiling cortex-m v0.6.7
[INFO] [stderr]    Compiling cortex-m v0.5.11
[INFO] [stderr]     Checking aligned v0.2.0
[INFO] [stderr]    Compiling cortex-m-semihosting v0.3.7
[INFO] [stderr]    Compiling cortex-m v0.4.3
[INFO] [stderr]    Compiling cc v1.0.67
[INFO] [stderr]    Compiling cortex-m-rtfm v0.3.4
[INFO] [stderr]     Checking untagged-option v0.1.1
[INFO] [stderr]     Checking aligned v0.1.2
[INFO] [stderr]     Checking bare-metal v0.1.3
[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" "8c145de1adafe25de26882e300a312320a0e606466f04ab2200e2387a19f08de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c145de1adafe25de26882e300a312320a0e606466f04ab2200e2387a19f08de", kill_on_drop: false }`
[INFO] [stdout] 8c145de1adafe25de26882e300a312320a0e606466f04ab2200e2387a19f08de