[INFO] fetching crate const-buffer 0.1.2...
[INFO] testing const-buffer-0.1.2 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate const-buffer 0.1.2 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate const-buffer 0.1.2
[INFO] finished tweaking crates.io crate const-buffer 0.1.2
[INFO] tweaked toml for crates.io crate const-buffer 0.1.2 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate const-buffer 0.1.2 on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "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-2025-09-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 324bbe8e8d11d41cdb6c55013d7cf9932fa02349dc553fba34b4b9126c258c0a
[INFO] running `Command { std: "docker" "start" "-a" "324bbe8e8d11d41cdb6c55013d7cf9932fa02349dc553fba34b4b9126c258c0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "324bbe8e8d11d41cdb6c55013d7cf9932fa02349dc553fba34b4b9126c258c0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "324bbe8e8d11d41cdb6c55013d7cf9932fa02349dc553fba34b4b9126c258c0a", kill_on_drop: false }`
[INFO] [stdout] 324bbe8e8d11d41cdb6c55013d7cf9932fa02349dc553fba34b4b9126c258c0a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d46afb68ebdf9c53d92c42378b0b7cb0f9871e9488efb7b9f7b95b1a0fad54c8
[INFO] running `Command { std: "docker" "start" "-a" "d46afb68ebdf9c53d92c42378b0b7cb0f9871e9488efb7b9f7b95b1a0fad54c8", kill_on_drop: false }`
[INFO] [stderr]    Compiling const-buffer v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]   --> src/lib.rs:70:5
[INFO] [stdout]    |
[INFO] [stdout] 70 |     untagged_unions
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]    |
[INFO] [stdout]    = note: removed in 1.64.0; see <https://github.com/rust-lang/rust/pull/97995> for more information
[INFO] [stdout]    = note: unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:62:1
[INFO] [stdout]    |
[INFO] [stdout] 62 | / #![feature(
[INFO] [stdout] 63 | |     associated_type_bounds,
[INFO] [stdout] 64 | |     const_fn_union,
[INFO] [stdout] 65 | |     min_const_generics,
[INFO] [stdout] ...  |
[INFO] [stdout] 70 | |     untagged_unions
[INFO] [stdout] 71 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout]    = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout]    = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout]    = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `associated_type_bounds` has been stable since 1.79.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:63:5
[INFO] [stdout]    |
[INFO] [stdout] 63 |     associated_type_bounds,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_fn_union` has been stable since 1.56.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:64:5
[INFO] [stdout]    |
[INFO] [stdout] 64 |     const_fn_union,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `min_const_generics` has been stable since 1.51.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |     min_const_generics,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_mut_refs` has been stable since 1.83.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:66:5
[INFO] [stdout]    |
[INFO] [stdout] 66 |     const_mut_refs,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `maybe_uninit_extra` has been stable since 1.60.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 |     maybe_uninit_extra,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `maybe_uninit_ref` has been stable since 1.55.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:68:5
[INFO] [stdout]    |
[INFO] [stdout] 68 |     maybe_uninit_ref,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
[INFO] [stdout]    --> src/lib.rs:112:13
[INFO] [stdout]     |
[INFO] [stdout] 112 |             maybe_uninit: MaybeUninit<[T; N]>,
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
[INFO] [stdout] help: wrap the field type in `ManuallyDrop<...>`
[INFO] [stdout]     |
[INFO] [stdout] 112 |             maybe_uninit: std::mem::ManuallyDrop<MaybeUninit<[T; N]>>,
[INFO] [stdout]     |                           +++++++++++++++++++++++                   +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no function or associated item named `slice_assume_init_ref` found for union `MaybeUninit<T>` in the current scope
[INFO] [stdout]    --> src/lib.rs:928:22
[INFO] [stdout]     |
[INFO] [stdout] 928 |         MaybeUninit::slice_assume_init_ref(self)
[INFO] [stdout]     |                      ^^^^^^^^^^^^^^^^^^^^^ function or associated item not found in `MaybeUninit<_>`
[INFO] [stdout]     |
[INFO] [stdout] note: if you're trying to build a new `MaybeUninit<_>` consider using one of the following associated functions:
[INFO] [stdout]       MaybeUninit::<T>::new
[INFO] [stdout]       MaybeUninit::<T>::uninit
[INFO] [stdout]       MaybeUninit::<T>::zeroed
[INFO] [stdout]    --> /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/mem/maybe_uninit.rs:307:5
[INFO] [stdout] help: there is a method `assume_init_ref` with a similar name, but with different arguments
[INFO] [stdout]    --> /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/mem/maybe_uninit.rs:782:5
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no function or associated item named `slice_assume_init_mut` found for union `MaybeUninit<T>` in the current scope
[INFO] [stdout]    --> src/lib.rs:932:22
[INFO] [stdout]     |
[INFO] [stdout] 932 |         MaybeUninit::slice_assume_init_mut(self)
[INFO] [stdout]     |                      ^^^^^^^^^^^^^^^^^^^^^ function or associated item not found in `MaybeUninit<_>`
[INFO] [stdout]     |
[INFO] [stdout] note: if you're trying to build a new `MaybeUninit<_>` consider using one of the following associated functions:
[INFO] [stdout]       MaybeUninit::<T>::new
[INFO] [stdout]       MaybeUninit::<T>::uninit
[INFO] [stdout]       MaybeUninit::<T>::zeroed
[INFO] [stdout]    --> /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/mem/maybe_uninit.rs:307:5
[INFO] [stdout] help: there is a method `assume_init_mut` with a similar name, but with different arguments
[INFO] [stdout]    --> /rustc/bb624dcb4c8ab987e10c0808d92d76f3b84dd117/library/core/src/mem/maybe_uninit.rs:899:5
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557, E0599, E0740.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-buffer` (lib) due to 5 previous errors; 6 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "d46afb68ebdf9c53d92c42378b0b7cb0f9871e9488efb7b9f7b95b1a0fad54c8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d46afb68ebdf9c53d92c42378b0b7cb0f9871e9488efb7b9f7b95b1a0fad54c8", kill_on_drop: false }`
[INFO] [stdout] d46afb68ebdf9c53d92c42378b0b7cb0f9871e9488efb7b9f7b95b1a0fad54c8
