[INFO] fetching crate variadic_monoids 0.1.1...
[INFO] testing variadic_monoids-0.1.1 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate variadic_monoids 0.1.1 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate variadic_monoids 0.1.1
[INFO] finished tweaking crates.io crate variadic_monoids 0.1.1
[INFO] tweaked toml for crates.io crate variadic_monoids 0.1.1 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate variadic_monoids 0.1.1 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 1 package to latest compatible version
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 3b0cf4abff5db53793fcadd5a32ff7bf549763b00c42dc97c14878a23577e38b
[INFO] running `Command { std: "docker" "start" "-a" "3b0cf4abff5db53793fcadd5a32ff7bf549763b00c42dc97c14878a23577e38b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3b0cf4abff5db53793fcadd5a32ff7bf549763b00c42dc97c14878a23577e38b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b0cf4abff5db53793fcadd5a32ff7bf549763b00c42dc97c14878a23577e38b", kill_on_drop: false }`
[INFO] [stdout] 3b0cf4abff5db53793fcadd5a32ff7bf549763b00c42dc97c14878a23577e38b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 75d706b957ed2e37da3fcf95017c2c8dd93af9a0c0a568759d3628a6b2ccb38f
[INFO] running `Command { std: "docker" "start" "-a" "75d706b957ed2e37da3fcf95017c2c8dd93af9a0c0a568759d3628a6b2ccb38f", kill_on_drop: false }`
[INFO] [stderr]    Compiling tuple_list v0.1.3
[INFO] [stderr]    Compiling variadic_monoids v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(const_fn)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.54.0; see <https://github.com/rust-lang/rust/pull/85109> for more information
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(const_generics)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.56.0; see <https://github.com/rust-lang/rust/pull/88369> for more information
[INFO] [stdout]   = note: removed in favor of `#![feature(adt_const_params)]` and `#![feature(generic_const_exprs)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:4:12
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(unsized_locals)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.89.0
[INFO] [stdout]   = note: removed due to implementation concerns; see https://github.com/rust-lang/rust/issues/111942
[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(fn_traits, unboxed_closures)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0059]: type parameter to bare `FnOnce` trait must be a tuple
[INFO] [stdout]   --> src/lib.rs:47:15
[INFO] [stdout]    |
[INFO] [stdout] 47 | impl<I, T, N> FnOnce<I> for VariFunc<T, N>
[INFO] [stdout]    |               ^^^^^^^^^ the nightly-only, unstable trait `std::marker::Tuple` is not implemented for `I`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `I` implements similarly named trait `tuple_list::Tuple`, but not `std::marker::Tuple`
[INFO] [stdout] note: required by a bound in `FnOnce`
[INFO] [stdout]   --> /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/core/src/ops/function.rs:242:0
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument
[INFO] [stdout]   --> src/lib.rs:54:5
[INFO] [stdout]    |
[INFO] [stdout] 54 |     extern "rust-call" fn call_once(self, args: I) -> T {
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the nightly-only, unstable trait `std::marker::Tuple` is not implemented for `I`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `I` implements similarly named trait `tuple_list::Tuple`, but not `std::marker::Tuple`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0059, E0277, E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0059`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `variadic_monoids` (lib) due to 6 previous errors
[INFO] running `Command { std: "docker" "inspect" "75d706b957ed2e37da3fcf95017c2c8dd93af9a0c0a568759d3628a6b2ccb38f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "75d706b957ed2e37da3fcf95017c2c8dd93af9a0c0a568759d3628a6b2ccb38f", kill_on_drop: false }`
[INFO] [stdout] 75d706b957ed2e37da3fcf95017c2c8dd93af9a0c0a568759d3628a6b2ccb38f
