[INFO] crate rclist 0.0.1 is already in cache
[INFO] extracting crate rclist 0.0.1 into work/ex/beta-1.38-1/sources/1.37.0/reg/rclist/0.0.1
[INFO] extracting crate rclist 0.0.1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rclist/0.0.1
[INFO] validating manifest of rclist-0.0.1 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 rclist-0.0.1 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 rclist-0.0.1
[INFO] finished frobbing rclist-0.0.1
[INFO] frobbed toml for rclist-0.0.1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/rclist/0.0.1/Cargo.toml
[INFO] started frobbing rclist-0.0.1
[INFO] finished frobbing rclist-0.0.1
[INFO] frobbed toml for rclist-0.0.1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rclist/0.0.1/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 rclist-0.0.1 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-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/rclist/0.0.1:/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" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] ec76cf717120a989c97059fb16a4b46023e45e2464094a43a1be42e9741fdb3c
[INFO] running `"docker" "start" "-a" "ec76cf717120a989c97059fb16a4b46023e45e2464094a43a1be42e9741fdb3c"`
[INFO] [stderr]    Compiling rclist v0.0.1 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(core)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(alloc)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `downgrade` found for type `&std::rc::Rc<T>` in the current scope
[INFO] [stderr]   --> src/lib.rs:31:50
[INFO] [stderr]    |
[INFO] [stderr] 31 |             &Link::Strong(ref x) => Link::Weak(x.downgrade()),
[INFO] [stderr]    |                                                --^^^^^^^^^
[INFO] [stderr]    |                                                | |
[INFO] [stderr]    |                                                | this is an associated function, not a method
[INFO] [stderr]    |                                                help: use associated function syntax instead: `&std::rc::Rc<T>::downgrade`
[INFO] [stderr]    |
[INFO] [stderr]    = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
[INFO] [stderr]    = note: the candidate is defined in an impl for the type `std::rc::Rc<_>`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rclist`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "ec76cf717120a989c97059fb16a4b46023e45e2464094a43a1be42e9741fdb3c"`
[INFO] running `"docker" "rm" "-f" "ec76cf717120a989c97059fb16a4b46023e45e2464094a43a1be42e9741fdb3c"`
[INFO] [stdout] ec76cf717120a989c97059fb16a4b46023e45e2464094a43a1be42e9741fdb3c