[INFO] fetching crate arduino_mkrzero 0.8.1...
[INFO] checking arduino_mkrzero-0.8.1 against beta for pr-78714
[INFO] extracting crate arduino_mkrzero 0.8.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate arduino_mkrzero 0.8.1 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-7/source/.cargo/config
[INFO] started tweaking crates.io crate arduino_mkrzero 0.8.1
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate arduino_mkrzero 0.8.1
[INFO] tweaked toml for crates.io crate arduino_mkrzero 0.8.1 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate crates.io crate arduino_mkrzero 0.8.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 72abfb84ee0e493f6400d6c98fd29e753aea447e5217e9dbadca752ca42324b4
[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" "72abfb84ee0e493f6400d6c98fd29e753aea447e5217e9dbadca752ca42324b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "72abfb84ee0e493f6400d6c98fd29e753aea447e5217e9dbadca752ca42324b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "72abfb84ee0e493f6400d6c98fd29e753aea447e5217e9dbadca752ca42324b4", kill_on_drop: false }`
[INFO] [stdout] 72abfb84ee0e493f6400d6c98fd29e753aea447e5217e9dbadca752ca42324b4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+beta" "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] 691ab599c12e356ba35319bfd51bc048cf3f3242a424484853d0b873955b40a6
[INFO] running `Command { std: "docker" "start" "-a" "691ab599c12e356ba35319bfd51bc048cf3f3242a424484853d0b873955b40a6", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.11.2
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling cortex-m v0.6.2
[INFO] [stderr]     Checking stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]    Compiling atsamd21g v0.8.0
[INFO] [stderr]     Checking nb v0.1.2
[INFO] [stderr]     Checking r0 v0.2.2
[INFO] [stderr]     Checking usb-device v0.2.7
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]    Compiling arduino_mkrzero v0.8.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking panic-halt v0.2.0
[INFO] [stderr]     Checking embedded-hal v0.2.3
[INFO] [stderr]     Checking usbd-serial v0.1.1
[INFO] [stderr]     Checking generic-array v0.13.2
[INFO] [stderr]     Checking generic-array v0.12.3
[INFO] [stderr]     Checking as-slice v0.1.3
[INFO] [stderr]     Checking aligned v0.3.2
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling cortex-m-rt-macros v0.1.8
[INFO] [stderr]    Compiling paste-impl v0.1.6
[INFO] [stderr]     Checking paste v0.1.6
[INFO] [stderr]     Checking atsamd-hal v0.10.0
[INFO] [stdout] error: duplicate lang item in crate `std` (which `test` depends on): `panic_impl`.
[INFO] [stdout]   |
[INFO] [stdout]   = note: the lang item is first defined in crate `panic_halt` (which `arduino_mkrzero` depends on)
[INFO] [stdout]   = note: first definition in `panic_halt` loaded from /opt/rustwide/target/debug/deps/libpanic_halt-e898de5af9d9d9bd.rmeta
[INFO] [stdout]   = note: second definition in `std` loaded from /opt/rustwide/rustup-home/toolchains/beta-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-3532beb752f910d7.rlib
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `arduino_mkrzero`
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[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" "691ab599c12e356ba35319bfd51bc048cf3f3242a424484853d0b873955b40a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "691ab599c12e356ba35319bfd51bc048cf3f3242a424484853d0b873955b40a6", kill_on_drop: false }`
[INFO] [stdout] 691ab599c12e356ba35319bfd51bc048cf3f3242a424484853d0b873955b40a6