[INFO] fetching crate keymatrix 0.1.2...
[INFO] checking keymatrix-0.1.2 against try#d990716b6a1fdde1300748828a9c9e79dfd0b898 for pr-74846
[INFO] extracting crate keymatrix 0.1.2 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate keymatrix 0.1.2 on toolchain d990716b6a1fdde1300748828a9c9e79dfd0b898
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d990716b6a1fdde1300748828a9c9e79dfd0b898" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate keymatrix 0.1.2
[INFO] finished tweaking crates.io crate keymatrix 0.1.2
[INFO] tweaked toml for crates.io crate keymatrix 0.1.2 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d990716b6a1fdde1300748828a9c9e79dfd0b898" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d990716b6a1fdde1300748828a9c9e79dfd0b898" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rtfm-core v0.2.0
[INFO] [stderr]   Downloaded panic-abort v0.2.0
[INFO] [stderr]   Downloaded cortex-m-rtfm-macros v0.3.2
[INFO] [stderr]   Downloaded samd21_mini v0.1.2
[INFO] [stderr]   Downloaded rtfm-syntax v0.3.4
[INFO] [stderr]   Downloaded atsamd21-hal v0.2.1
[INFO] [stderr]   Downloaded cortex-m-rtfm v0.3.4
[INFO] [stderr]   Downloaded cortex-m v0.3.1
[INFO] [stderr]   Downloaded atsamd-hal v0.4.1
[INFO] [stderr]   Downloaded samd21g18a v0.2.1
[INFO] [stderr]   Downloaded atsamd21g18a v0.4.0
[INFO] [stderr]   Downloaded atsamd21g18a v0.3.1
[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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+d990716b6a1fdde1300748828a9c9e79dfd0b898" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8c632f2744fd65da4ad345fb9c546cd0685e126d8032c7a1aca8640041de81c9
[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" "8c632f2744fd65da4ad345fb9c546cd0685e126d8032c7a1aca8640041de81c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c632f2744fd65da4ad345fb9c546cd0685e126d8032c7a1aca8640041de81c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c632f2744fd65da4ad345fb9c546cd0685e126d8032c7a1aca8640041de81c9", kill_on_drop: false }`
[INFO] [stdout] 8c632f2744fd65da4ad345fb9c546cd0685e126d8032c7a1aca8640041de81c9
[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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+d990716b6a1fdde1300748828a9c9e79dfd0b898" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b8a2774cbd4f01914b1e3285c5be34d0c05e8b70eddceb3cadd96cc98e405718
[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" "b8a2774cbd4f01914b1e3285c5be34d0c05e8b70eddceb3cadd96cc98e405718", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]     Checking vcell v0.1.2
[INFO] [stderr]    Compiling syn v1.0.38
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling cortex-m v0.6.3
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling cortex-m v0.5.10
[INFO] [stderr]     Checking aligned v0.2.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling gimli v0.22.0
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]    Compiling adler v0.2.3
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]    Compiling object v0.20.0
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling rustc-demangle v0.1.16
[INFO] [stderr]     Checking r0 v0.2.2
[INFO] [stderr]    Compiling proc-macro-hack v0.5.18
[INFO] [stderr]     Checking aligned v0.1.2
[INFO] [stderr]    Compiling atsamd21g18a v0.4.0
[INFO] [stderr]     Checking bare-metal v0.1.3
[INFO] [stderr]    Compiling either v1.6.0
[INFO] [stderr]    Compiling cortex-m v0.3.1
[INFO] [stderr]    Compiling atsamd21g18a v0.3.1
[INFO] [stderr]    Compiling cortex-m v0.4.3
[INFO] [stderr]    Compiling cortex-m-rtfm v0.3.4
[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" "b8a2774cbd4f01914b1e3285c5be34d0c05e8b70eddceb3cadd96cc98e405718", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8a2774cbd4f01914b1e3285c5be34d0c05e8b70eddceb3cadd96cc98e405718", kill_on_drop: false }`
[INFO] [stdout] b8a2774cbd4f01914b1e3285c5be34d0c05e8b70eddceb3cadd96cc98e405718