[INFO] fetching crate mwatch-sdk 0.4.0...
[INFO] checking mwatch-sdk-0.4.0 against beta for pr-78714
[INFO] extracting crate mwatch-sdk 0.4.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate mwatch-sdk 0.4.0 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-0/source/.cargo/config
[INFO] started tweaking crates.io crate mwatch-sdk 0.4.0
[INFO] finished tweaking crates.io crate mwatch-sdk 0.4.0
[INFO] tweaked toml for crates.io crate mwatch-sdk 0.4.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 2c47ac04f0212c8131d7b279378c56eeaebc2a292d5d06fa833c526776cf8245
[INFO] running `Command { std: "docker" "start" "-a" "2c47ac04f0212c8131d7b279378c56eeaebc2a292d5d06fa833c526776cf8245", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2c47ac04f0212c8131d7b279378c56eeaebc2a292d5d06fa833c526776cf8245", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2c47ac04f0212c8131d7b279378c56eeaebc2a292d5d06fa833c526776cf8245", kill_on_drop: false }`
[INFO] [stdout] 2c47ac04f0212c8131d7b279378c56eeaebc2a292d5d06fa833c526776cf8245
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stdout] 2b3f9aa68716ede4faea5db8591bd52a2ffeb91af2aa8eff777726c7490fa801
[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" "2b3f9aa68716ede4faea5db8591bd52a2ffeb91af2aa8eff777726c7490fa801", kill_on_drop: false }`
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling heapless v0.4.4
[INFO] [stderr]    Compiling stm32l4 v0.7.1
[INFO] [stderr]    Compiling cortex-m-rtfm v0.4.3
[INFO] [stderr]    Compiling mwatch_kernel v1.0.0
[INFO] [stderr]    Compiling mwatch-sdk v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking simple-hex v0.1.0
[INFO] [stderr]    Compiling nom v5.1.2
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling crc v1.8.1
[INFO] [stderr]     Checking generic-array v0.11.1
[INFO] [stderr]     Checking max17048 v0.1.0
[INFO] [stderr]     Checking hash32 v0.1.1
[INFO] [stderr]     Checking cortex-m-rt v0.6.13
[INFO] [stderr]     Checking panic-itm v0.4.1
[INFO] [stderr]     Checking cortex-m-log v0.4.0
[INFO] [stderr]     Checking panic-semihosting v0.5.4
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/heapless-0.4.4/src/lib.rs:92:35
[INFO] [stdout]    |
[INFO] [stdout] 92 | #![cfg_attr(feature = "const-fn", feature(const_fn))]
[INFO] [stdout]    |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/heapless-0.4.4/src/lib.rs:93:35
[INFO] [stdout]    |
[INFO] [stdout] 93 | #![cfg_attr(feature = "const-fn", feature(untagged_unions))]
[INFO] [stdout]    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `heapless`
[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" "2b3f9aa68716ede4faea5db8591bd52a2ffeb91af2aa8eff777726c7490fa801", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b3f9aa68716ede4faea5db8591bd52a2ffeb91af2aa8eff777726c7490fa801", kill_on_drop: false }`
[INFO] [stdout] 2b3f9aa68716ede4faea5db8591bd52a2ffeb91af2aa8eff777726c7490fa801