[INFO] crate samd21g18a 0.2.1 is already in cache
[INFO] extracting crate samd21g18a 0.2.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/samd21g18a/0.2.1
[INFO] extracting crate samd21g18a 0.2.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/samd21g18a/0.2.1
[INFO] validating manifest of samd21g18a-0.2.1 on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of samd21g18a-0.2.1 on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing samd21g18a-0.2.1
[INFO] finished frobbing samd21g18a-0.2.1
[INFO] frobbed toml for samd21g18a-0.2.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/samd21g18a/0.2.1/Cargo.toml
[INFO] started frobbing samd21g18a-0.2.1
[INFO] finished frobbing samd21g18a-0.2.1
[INFO] frobbed toml for samd21g18a-0.2.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/samd21g18a/0.2.1/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing samd21g18a-0.2.1 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-0/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/samd21g18a/0.2.1:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] d2f4274d5896f092244619c360ab5c7266a522ff113862cc862c07e1a48968ec
[INFO] running `"docker" "start" "-a" "d2f4274d5896f092244619c360ab5c7266a522ff113862cc862c07e1a48968ec"`
[INFO] [stderr]    Compiling vcell v0.1.0
[INFO] [stderr]    Compiling cortex-m v0.3.1
[INFO] [stderr]    Compiling bare-metal v0.1.3
[INFO] [stderr]    Compiling aligned v0.1.2
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/bare-metal-0.1.3/src/lib.rs:5:35
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![cfg_attr(feature = "const-fn", feature(const_fn))]
[INFO] [stderr]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/aligned-0.1.2/src/lib.rs:32:35
[INFO] [stderr]    |
[INFO] [stderr] 32 | #![cfg_attr(feature = "const-fn", feature(const_fn))]
[INFO] [stderr]    |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `bare-metal`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `aligned`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "d2f4274d5896f092244619c360ab5c7266a522ff113862cc862c07e1a48968ec"`
[INFO] running `"docker" "rm" "-f" "d2f4274d5896f092244619c360ab5c7266a522ff113862cc862c07e1a48968ec"`
[INFO] [stdout] d2f4274d5896f092244619c360ab5c7266a522ff113862cc862c07e1a48968ec