[INFO] crate rclist 0.0.1 is already in cache
[INFO] testing rclist-0.0.1 against 1.44.0 for beta-1.45-1
[INFO] extracting crate rclist 0.0.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate rclist 0.0.1 on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate rclist 0.0.1
[INFO] finished tweaking crates.io crate rclist 0.0.1
[INFO] tweaked toml for crates.io crate rclist 0.0.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 839c3edc5ed761963c89d44fefb8d20c95fd3d8e2c5c116d74b4f91f88e93887
[INFO] running `"docker" "start" "-a" "839c3edc5ed761963c89d44fefb8d20c95fd3d8e2c5c116d74b4f91f88e93887"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rclist v0.0.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable 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 stable 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 reference `&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<T>`
[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" "839c3edc5ed761963c89d44fefb8d20c95fd3d8e2c5c116d74b4f91f88e93887"`
[INFO] running `"docker" "rm" "-f" "839c3edc5ed761963c89d44fefb8d20c95fd3d8e2c5c116d74b4f91f88e93887"`
[INFO] [stdout] 839c3edc5ed761963c89d44fefb8d20c95fd3d8e2c5c116d74b4f91f88e93887