[INFO] crate iobuf 5.8.1 is already in cache
[INFO] extracting crate iobuf 5.8.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/iobuf/5.8.1
[INFO] extracting crate iobuf 5.8.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/iobuf/5.8.1
[INFO] validating manifest of iobuf-5.8.1 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of iobuf-5.8.1 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing iobuf-5.8.1
[INFO] finished frobbing iobuf-5.8.1
[INFO] frobbed toml for iobuf-5.8.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/iobuf/5.8.1/Cargo.toml
[INFO] started frobbing iobuf-5.8.1
[INFO] finished frobbing iobuf-5.8.1
[INFO] frobbed toml for iobuf-5.8.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/iobuf/5.8.1/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing iobuf-5.8.1 against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-5/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/iobuf/5.8.1:/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] 406506c8e9ef824080a089a45a7a71592304ffa8d17c82b892b706fabd0adc8c
[INFO] running `"docker" "start" "-a" "406506c8e9ef824080a089a45a7a71592304ffa8d17c82b892b706fabd0adc8c"`
[INFO] [stderr] warning: profile `doc` is deprecated and has no effect
[INFO] [stderr]    Compiling iobuf v5.8.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0432]: unresolved import `alloc::heap`
[INFO] [stderr]  --> src/raw.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | use alloc::heap::{Heap, Alloc, Layout};
[INFO] [stderr]   |            ^^^^ could not find `heap` in `alloc`
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `core::nonzero`
[INFO] [stderr]  --> src/raw.rs:4:11
[INFO] [stderr]   |
[INFO] [stderr] 4 | use core::nonzero::NonZero;
[INFO] [stderr]   |           ^^^^^^^ could not find `nonzero` in `core`
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `core::nonzero`
[INFO] [stderr]  --> src/iobuf.rs:1:11
[INFO] [stderr]   |
[INFO] [stderr] 1 | use core::nonzero::NonZero;
[INFO] [stderr]   |           ^^^^^^^ could not find `nonzero` in `core`
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `core::nonzero`
[INFO] [stderr]  --> src/impls.rs:1:11
[INFO] [stderr]   |
[INFO] [stderr] 1 | use core::nonzero::NonZero;
[INFO] [stderr]   |           ^^^^^^^ could not find `nonzero` in `core`
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:42:1
[INFO] [stderr]    |
[INFO] [stderr] 42 | #![feature(plugin)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:43:1
[INFO] [stderr]    |
[INFO] [stderr] 43 | #![feature(core_intrinsics)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:44:1
[INFO] [stderr]    |
[INFO] [stderr] 44 | #![feature(nonzero)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:45:1
[INFO] [stderr]    |
[INFO] [stderr] 45 | #![feature(allocator_api)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:46:1
[INFO] [stderr]    |
[INFO] [stderr] 46 | #![feature(alloc)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:47:1
[INFO] [stderr]    |
[INFO] [stderr] 47 | #![feature(unique)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'ptr_internals': use NonNull instead and consider PhantomData<T> (if you also use #[may_dangle]), Send, and/or Sync
[INFO] [stderr]  --> src/raw.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use core::ptr::Unique;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'ptr_internals': use NonNull instead and consider PhantomData<T> (if you also use #[may_dangle]), Send, and/or Sync
[INFO] [stderr]    --> src/raw.rs:354:37
[INFO] [stderr]     |
[INFO] [stderr] 354 |       buf:    unsafe { NonZero::new(Unique::empty().as_ptr()) },
[INFO] [stderr]     |                                     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'ptr_internals'
[INFO] [stderr]    --> src/raw.rs:354:37
[INFO] [stderr]     |
[INFO] [stderr] 354 |       buf:    unsafe { NonZero::new(Unique::empty().as_ptr()) },
[INFO] [stderr]     |                                     ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0658]: use of unstable library feature 'ptr_internals'
[INFO] [stderr]    --> src/raw.rs:354:53
[INFO] [stderr]     |
[INFO] [stderr] 354 |       buf:    unsafe { NonZero::new(Unique::empty().as_ptr()) },
[INFO] [stderr]     |                                                     ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 14 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0432, E0554, E0658.
[INFO] [stderr] For more information about an error, try `rustc --explain E0432`.
[INFO] [stderr] error: Could not compile `iobuf`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "406506c8e9ef824080a089a45a7a71592304ffa8d17c82b892b706fabd0adc8c"`
[INFO] running `"docker" "rm" "-f" "406506c8e9ef824080a089a45a7a71592304ffa8d17c82b892b706fabd0adc8c"`
[INFO] [stdout] 406506c8e9ef824080a089a45a7a71592304ffa8d17c82b892b706fabd0adc8c