[INFO] fetching crate shared_slice 0.0.4...
[INFO] testing shared_slice-0.0.4 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate shared_slice 0.0.4 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate shared_slice 0.0.4
[INFO] finished tweaking crates.io crate shared_slice 0.0.4
[INFO] tweaked toml for crates.io crate shared_slice 0.0.4 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate shared_slice 0.0.4 on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 10 packages to latest compatible versions
[INFO] [stderr]       Adding rand v0.3.23 (available: v0.10.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 37e1ce14ce9b03b68996d2c073e5f6e820a2de68426c880b14d9faa0639a3bc5
[INFO] running `Command { std: "docker" "start" "-a" "37e1ce14ce9b03b68996d2c073e5f6e820a2de68426c880b14d9faa0639a3bc5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "37e1ce14ce9b03b68996d2c073e5f6e820a2de68426c880b14d9faa0639a3bc5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37e1ce14ce9b03b68996d2c073e5f6e820a2de68426c880b14d9faa0639a3bc5", kill_on_drop: false }`
[INFO] [stdout] 37e1ce14ce9b03b68996d2c073e5f6e820a2de68426c880b14d9faa0639a3bc5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c6d7ac1b94382ce5b0953872e58d439f951187f9dde207f4296bd604bfe11230
[INFO] running `Command { std: "docker" "start" "-a" "c6d7ac1b94382ce5b0953872e58d439f951187f9dde207f4296bd604bfe11230", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling shared_slice v0.0.4 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0259]: the name `core` is defined multiple times
[INFO] [stdout]   --> src/lib.rs:79:1
[INFO] [stdout]    |
[INFO] [stdout] 79 | extern crate core;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^ `core` reimported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `core` must be defined only once in the type namespace of this module
[INFO] [stdout] help: you can use `as` to change the binding name of the import
[INFO] [stdout]    |
[INFO] [stdout] 79 | extern crate core as other_core;
[INFO] [stdout]    |                   +++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0432]: unresolved import `alloc::arc`
[INFO] [stdout]  --> src/arc.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 8 | use alloc::arc::{Arc, Weak};
[INFO] [stdout]   |            ^^^ could not find `arc` in `alloc`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(no_std)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `no_std` has been stable since `1.6.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::prelude::*`
[INFO] [stdout]  --> src/rc.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use core::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::prelude::*`
[INFO] [stdout]  --> src/arc.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use core::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `no_std` has been stable since 1.6.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(no_std)]
[INFO] [stdout]   |            ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `core` has been stable since 1.6.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:76:12
[INFO] [stdout]    |
[INFO] [stdout] 76 | #![feature(core, alloc)]
[INFO] [stdout]    |            ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `alloc` has been stable since 1.36.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:76:18
[INFO] [stdout]    |
[INFO] [stdout] 76 | #![feature(core, alloc)]
[INFO] [stdout]    |                  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `downgrade` found for struct `Rc<Box<[T]>>` in the current scope
[INFO] [stdout]   --> src/rc.rs:73:33
[INFO] [stdout]    |
[INFO] [stdout] 73 |             counts: self.counts.downgrade()
[INFO] [stdout]    |                                 ^^^^^^^^^ this is an associated function, not a method
[INFO] [stdout]    |
[INFO] [stdout]    = note: found the following associated functions; to be used as methods, functions must have a `self` parameter
[INFO] [stdout]    = note: the candidate is defined in an impl for the type `Rc<T, A>`
[INFO] [stdout] help: use associated function syntax instead
[INFO] [stdout]    |
[INFO] [stdout] 73 -             counts: self.counts.downgrade()
[INFO] [stdout] 73 +             counts: Rc::<Box<[T]>>::downgrade(&self.counts)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0259, E0432, E0554, E0599.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0259`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `shared_slice` (lib) due to 4 previous errors; 5 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "c6d7ac1b94382ce5b0953872e58d439f951187f9dde207f4296bd604bfe11230", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c6d7ac1b94382ce5b0953872e58d439f951187f9dde207f4296bd604bfe11230", kill_on_drop: false }`
[INFO] [stdout] c6d7ac1b94382ce5b0953872e58d439f951187f9dde207f4296bd604bfe11230
