[INFO] crate slab_allocator 0.3.5 is already in cache
[INFO] extracting crate slab_allocator 0.3.5 into work/ex/beta-1.38-1/sources/1.37.0/reg/slab_allocator/0.3.5
[INFO] extracting crate slab_allocator 0.3.5 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/slab_allocator/0.3.5
[INFO] validating manifest of slab_allocator-0.3.5 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 slab_allocator-0.3.5 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 slab_allocator-0.3.5
[INFO] finished frobbing slab_allocator-0.3.5
[INFO] frobbed toml for slab_allocator-0.3.5 written to work/ex/beta-1.38-1/sources/1.37.0/reg/slab_allocator/0.3.5/Cargo.toml
[INFO] started frobbing slab_allocator-0.3.5
[INFO] finished frobbing slab_allocator-0.3.5
[INFO] frobbed toml for slab_allocator-0.3.5 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/slab_allocator/0.3.5/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 slab_allocator-0.3.5 against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/reg/slab_allocator/0.3.5:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] d57914738c3b034823184815285b18fe7137c9fb834a65f43eab9a6f4c544b41
[INFO] running `"docker" "start" "-a" "d57914738c3b034823184815285b18fe7137c9fb834a65f43eab9a6f4c544b41"`
[INFO] [stderr]    Compiling spin v0.4.10
[INFO] [stderr]    Compiling linked_list_allocator v0.6.4
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/linked_list_allocator-0.6.4/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(const_fn)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/linked_list_allocator-0.6.4/src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(alloc, allocator_api)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.10/src/lib.rs:6:35
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stderr]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `linked_list_allocator`.
[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 `spin`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d57914738c3b034823184815285b18fe7137c9fb834a65f43eab9a6f4c544b41"`
[INFO] running `"docker" "rm" "-f" "d57914738c3b034823184815285b18fe7137c9fb834a65f43eab9a6f4c544b41"`
[INFO] [stdout] d57914738c3b034823184815285b18fe7137c9fb834a65f43eab9a6f4c544b41