[INFO] crate strong_rc 0.1.4 is already in cache
[INFO] extracting crate strong_rc 0.1.4 into work/ex/beta-1.38-1/sources/1.37.0/reg/strong_rc/0.1.4
[INFO] extracting crate strong_rc 0.1.4 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/strong_rc/0.1.4
[INFO] validating manifest of strong_rc-0.1.4 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 strong_rc-0.1.4 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 strong_rc-0.1.4
[INFO] finished frobbing strong_rc-0.1.4
[INFO] frobbed toml for strong_rc-0.1.4 written to work/ex/beta-1.38-1/sources/1.37.0/reg/strong_rc/0.1.4/Cargo.toml
[INFO] started frobbing strong_rc-0.1.4
[INFO] finished frobbing strong_rc-0.1.4
[INFO] frobbed toml for strong_rc-0.1.4 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/strong_rc/0.1.4/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 strong_rc-0.1.4 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/strong_rc/0.1.4:/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] 905a1c9cf7de021f78020bf8f72f16756ec5093e33a58e62a921c9a33747dcad
[INFO] running `"docker" "start" "-a" "905a1c9cf7de021f78020bf8f72f16756ec5093e33a58e62a921c9a33747dcad"`
[INFO] [stderr]    Compiling strong_rc v0.1.4 (/opt/crater/workdir)
[INFO] [stderr] error[E0432]: unresolved import `alloc::heap`
[INFO] [stderr]    --> src/lib.rs:128:5
[INFO] [stderr]     |
[INFO] [stderr] 128 | use alloc::heap;
[INFO] [stderr]     |     ^^^^^^^^^^^ no `heap` in the root
[INFO] [stderr] 
[INFO] [stderr] error[E0432]: unresolved import `std::ptr::Shared`
[INFO] [stderr]    --> src/lib.rs:139:22
[INFO] [stderr]     |
[INFO] [stderr] 139 | use std::ptr::{self, Shared};
[INFO] [stderr]     |                      ^^^^^^ no `Shared` in `ptr`
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:120:1
[INFO] [stderr]     |
[INFO] [stderr] 120 | #![feature(shared)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:121:1
[INFO] [stderr]     |
[INFO] [stderr] 121 | #![feature(process_abort)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:122:1
[INFO] [stderr]     |
[INFO] [stderr] 122 | #![feature(optin_builtin_traits)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:123:1
[INFO] [stderr]     |
[INFO] [stderr] 123 | #![feature(unsize, coerce_unsized)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:124:1
[INFO] [stderr]     |
[INFO] [stderr] 124 | #![feature(specialization)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]    --> src/lib.rs:125:1
[INFO] [stderr]     |
[INFO] [stderr] 125 | #![feature(alloc, heap_api)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0374]: the trait `CoerceUnsized` may only be implemented for a coercion between structures with one field being coerced, none found
[INFO] [stderr]    --> src/lib.rs:190:1
[INFO] [stderr]     |
[INFO] [stderr] 190 | / impl<T, U> CoerceUnsized<Rc<U>> for Rc<T>
[INFO] [stderr] 191 | | where T: ?Sized + Unsize<U>,
[INFO] [stderr] 192 | |       U: ?Sized {}
[INFO] [stderr]     | |__________________^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 9 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0374, E0432, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0374`.
[INFO] [stderr] error: Could not compile `strong_rc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "905a1c9cf7de021f78020bf8f72f16756ec5093e33a58e62a921c9a33747dcad"`
[INFO] running `"docker" "rm" "-f" "905a1c9cf7de021f78020bf8f72f16756ec5093e33a58e62a921c9a33747dcad"`
[INFO] [stdout] 905a1c9cf7de021f78020bf8f72f16756ec5093e33a58e62a921c9a33747dcad