[INFO] fetching crate barebones-watchface 2.1.1...
[INFO] testing barebones-watchface-2.1.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate barebones-watchface 2.1.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate barebones-watchface 2.1.1 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate barebones-watchface 2.1.1
[INFO] finished tweaking crates.io crate barebones-watchface 2.1.1
[INFO] tweaked toml for crates.io crate barebones-watchface 2.1.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 887e1bbe4f96f7ade21ce3a860e410a176bc0e5959ce5bd9ac42eec239e84a98
[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" "887e1bbe4f96f7ade21ce3a860e410a176bc0e5959ce5bd9ac42eec239e84a98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "887e1bbe4f96f7ade21ce3a860e410a176bc0e5959ce5bd9ac42eec239e84a98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "887e1bbe4f96f7ade21ce3a860e410a176bc0e5959ce5bd9ac42eec239e84a98", kill_on_drop: false }`
[INFO] [stdout] 887e1bbe4f96f7ade21ce3a860e410a176bc0e5959ce5bd9ac42eec239e84a98
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4fcfe5fb17d7c3f3458350f6d766cc115ad80fb71121401b225318601418237d
[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" "4fcfe5fb17d7c3f3458350f6d766cc115ad80fb71121401b225318601418237d", kill_on_drop: false }`
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.6.4
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling cty v0.1.5
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling heapless v0.5.6
[INFO] [stderr]    Compiling cty v0.2.1
[INFO] [stderr]    Compiling cortex-m-semihosting v0.3.7
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling rustc-serialize v0.3.24
[INFO] [stderr]    Compiling arrayvec v0.5.2
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling hash32 v0.1.1
[INFO] [stderr]    Compiling as-slice v0.1.4
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling embedded-hal v0.2.4
[INFO] [stderr]    Compiling cstr_core v0.1.2
[INFO] [stderr]    Compiling aligned v0.3.4
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/cortex-m-0.6.4/src/lib.rs:32:37
[INFO] [stdout]    |
[INFO] [stdout] 32 | #![cfg_attr(feature = "inline-asm", feature(llvm_asm))]
[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 E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `cortex-m`
[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" "4fcfe5fb17d7c3f3458350f6d766cc115ad80fb71121401b225318601418237d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4fcfe5fb17d7c3f3458350f6d766cc115ad80fb71121401b225318601418237d", kill_on_drop: false }`
[INFO] [stdout] 4fcfe5fb17d7c3f3458350f6d766cc115ad80fb71121401b225318601418237d