[INFO] fetching crate nrf52840 0.2.0...
[INFO] testing nrf52840-0.2.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate nrf52840 0.2.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate nrf52840 0.2.0 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nrf52840 0.2.0
[INFO] finished tweaking crates.io crate nrf52840 0.2.0
[INFO] tweaked toml for crates.io crate nrf52840 0.2.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--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-rt v0.5.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] cf8d5b08a453d20dd8d4c9958bfc33cae66a25a140374da01e60833342d37b99
[INFO] running `Command { std: "docker" "start" "-a" "cf8d5b08a453d20dd8d4c9958bfc33cae66a25a140374da01e60833342d37b99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "cf8d5b08a453d20dd8d4c9958bfc33cae66a25a140374da01e60833342d37b99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cf8d5b08a453d20dd8d4c9958bfc33cae66a25a140374da01e60833342d37b99", kill_on_drop: false }`
[INFO] [stdout] cf8d5b08a453d20dd8d4c9958bfc33cae66a25a140374da01e60833342d37b99
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7c8d81927837c5e6f0d4aead4ba46f1d592f8b324d06a2122f3544ce27aa855b
[INFO] running `Command { std: "docker" "start" "-a" "7c8d81927837c5e6f0d4aead4ba46f1d592f8b324d06a2122f3544ce27aa855b", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling cortex-m v0.7.3
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.6.7
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling cortex-m v0.5.11
[INFO] [stderr]    Compiling aligned v0.2.0
[INFO] [stderr]    Compiling nrf52840 v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling generic-array v0.13.3
[INFO] [stderr]    Compiling generic-array v0.12.4
[INFO] [stderr]    Compiling volatile-register v0.2.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling as-slice v0.1.5
[INFO] [stderr]    Compiling embedded-hal v0.2.6
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling aligned v0.3.5
[INFO] [stdout] warning: lint `private_no_mangle_statics` has been removed: no longer a warning, `#[no_mangle]` statics always exported
[INFO] [stdout]     --> src/lib.rs:1643:9
[INFO] [stdout]      |
[INFO] [stdout] 1643 | #[allow(private_no_mangle_statics)]
[INFO] [stdout]      |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]      |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]     --> src/lib.rs:3:9
[INFO] [stdout]      |
[INFO] [stdout] 3    | #![deny(warnings)]
[INFO] [stdout]      |         ^^^^^^^^
[INFO] [stdout]      = note: `#[warn(renamed_and_removed_lints)]` implied by `#[warn(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(untagged_unions)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `nrf52840` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "7c8d81927837c5e6f0d4aead4ba46f1d592f8b324d06a2122f3544ce27aa855b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c8d81927837c5e6f0d4aead4ba46f1d592f8b324d06a2122f3544ce27aa855b", kill_on_drop: false }`
[INFO] [stdout] 7c8d81927837c5e6f0d4aead4ba46f1d592f8b324d06a2122f3544ce27aa855b