[INFO] crate capnp-nonblock 0.4.0 is already in cache
[INFO] extracting crate capnp-nonblock 0.4.0 into work/ex/beta-1.37-6/sources/1.36.0/reg/capnp-nonblock/0.4.0
[INFO] extracting crate capnp-nonblock 0.4.0 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/capnp-nonblock/0.4.0
[INFO] validating manifest of capnp-nonblock-0.4.0 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 capnp-nonblock-0.4.0 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 capnp-nonblock-0.4.0
[INFO] finished frobbing capnp-nonblock-0.4.0
[INFO] frobbed toml for capnp-nonblock-0.4.0 written to work/ex/beta-1.37-6/sources/1.36.0/reg/capnp-nonblock/0.4.0/Cargo.toml
[INFO] started frobbing capnp-nonblock-0.4.0
[INFO] finished frobbing capnp-nonblock-0.4.0
[INFO] frobbed toml for capnp-nonblock-0.4.0 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/capnp-nonblock/0.4.0/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 capnp-nonblock-0.4.0 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-3/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/capnp-nonblock/0.4.0:/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] f24f3b1c02ed680d4e12916ae3ed92d2e26d092ca862b131c40df5ebc8bf066f
[INFO] running `"docker" "start" "-a" "f24f3b1c02ed680d4e12916ae3ed92d2e26d092ca862b131c40df5ebc8bf066f"`
[INFO] [stderr]    Compiling quickcheck v0.2.27
[INFO] [stderr]    Compiling capnp v0.6.2
[INFO] [stderr] warning[E0502]: cannot borrow `*reff` as immutable because it is also borrowed as mutable
[INFO] [stderr]    --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/capnp-0.6.2/src/private/layout.rs:639:47
[INFO] [stderr]     |
[INFO] [stderr] 639 |         let ptr = try!(follow_fars(&mut reff, (*reff).target(), &mut segment));
[INFO] [stderr]     |                        ----------- ---------  ^^^^^^^ immutable borrow occurs here
[INFO] [stderr]     |                        |           |
[INFO] [stderr]     |                        |           mutable borrow occurs here
[INFO] [stderr]     |                        mutable borrow later used by call
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]     = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr] 
[INFO] [stderr]    Compiling capnp-nonblock v0.4.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0432]: unresolved import `alloc::heap`
[INFO] [stderr]  --> src/buf.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[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | #![feature(alloc, allocator_api)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0432, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0432`.
[INFO] [stderr] error: Could not compile `capnp-nonblock`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "f24f3b1c02ed680d4e12916ae3ed92d2e26d092ca862b131c40df5ebc8bf066f"`
[INFO] running `"docker" "rm" "-f" "f24f3b1c02ed680d4e12916ae3ed92d2e26d092ca862b131c40df5ebc8bf066f"`
[INFO] [stdout] f24f3b1c02ed680d4e12916ae3ed92d2e26d092ca862b131c40df5ebc8bf066f