[INFO] updating cached repository swarajd/rust_kernel
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/swarajd/rust_kernel
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/swarajd/rust_kernel" "work/ex/beta-1.38-1/sources/1.37.0/gh/swarajd/rust_kernel"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/swarajd/rust_kernel'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/swarajd/rust_kernel" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/swarajd/rust_kernel"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/swarajd/rust_kernel'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9b67adfab389e09319500de3fb67acdded7f23ec
[INFO] sha for GitHub repo swarajd/rust_kernel: 9b67adfab389e09319500de3fb67acdded7f23ec
[INFO] validating manifest of swarajd/rust_kernel 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 swarajd/rust_kernel 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 swarajd/rust_kernel
[INFO] finished frobbing swarajd/rust_kernel
[INFO] frobbed toml for swarajd/rust_kernel written to work/ex/beta-1.38-1/sources/1.37.0/gh/swarajd/rust_kernel/Cargo.toml
[INFO] started frobbing swarajd/rust_kernel
[INFO] finished frobbing swarajd/rust_kernel
[INFO] frobbed toml for swarajd/rust_kernel written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/swarajd/rust_kernel/Cargo.toml
[INFO] crate swarajd/rust_kernel already has a lockfile, it will not be regenerated
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing swarajd/rust_kernel 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-6/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/swarajd/rust_kernel:/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] d3fe7e56cc82f0255d26d077af825d2b019dc1668a7da745dd30699c745dc25a
[INFO] running `"docker" "start" "-a" "d3fe7e56cc82f0255d26d077af825d2b019dc1668a7da745dd30699c745dc25a"`
[INFO] [stderr]    Compiling volatile v0.1.0
[INFO] [stderr]    Compiling spin v0.4.5
[INFO] [stderr]    Compiling rlibc v1.0.0
[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/spin-0.4.5/src/lib.rs:6:30
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![cfg_attr(feature = "asm", feature(asm))]
[INFO] [stderr]   |                              ^^^^^^^^^^^^
[INFO] [stderr] 
[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/spin-0.4.5/src/lib.rs:7:42
[INFO] [stderr]   |
[INFO] [stderr] 7 | #![cfg_attr(feature = "core_intrinsics", feature(core_intrinsics))]
[INFO] [stderr]   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[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/spin-0.4.5/src/lib.rs:8:35
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stderr]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `spin`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d3fe7e56cc82f0255d26d077af825d2b019dc1668a7da745dd30699c745dc25a"`
[INFO] running `"docker" "rm" "-f" "d3fe7e56cc82f0255d26d077af825d2b019dc1668a7da745dd30699c745dc25a"`
[INFO] [stdout] d3fe7e56cc82f0255d26d077af825d2b019dc1668a7da745dd30699c745dc25a