chore: release v0.30.0

[github-actions]

🤖 New release

• timely_bytes: 0.29.0 -> 0.30.0
• timely_container: 0.29.0 -> 0.30.0
• timely_logging: 0.29.0 -> 0.30.0
• timely_communication: 0.29.0 -> 0.30.0 (⚠ API breaking changes)
• timely: 0.29.0 -> 0.30.0

⚠ timely_communication breaking changes

--- failure auto_trait_impl_removed: auto trait no longer implemented ---

Description:
A public type has stopped implementing one or more auto traits. This can break downstream code that depends on the traits being implemented.
        ref: https://doc.rust-lang.org/reference/special-types-and-traits.html#auto-traits
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/auto_trait_impl_removed.ron

Failed in:
  type MergeQueue is no longer Sync, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/bytes_exchange.rs:33
  type MergeQueue is no longer UnwindSafe, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/bytes_exchange.rs:33
  type MergeQueue is no longer RefUnwindSafe, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/bytes_exchange.rs:33

--- failure derive_trait_impl_removed: built-in derived trait no longer implemented ---

Description:
A public type has stopped deriving one or more traits. This can break downstream code that depends on those types implementing those traits.
        ref: https://doc.rust-lang.org/reference/attributes/derive.html#derive
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/derive_trait_impl_removed.ron

Failed in:
  type MergeQueue no longer derives Clone, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/bytes_exchange.rs:33

--- failure enum_struct_variant_field_missing: pub enum struct variant's field removed or renamed ---

Description:
A publicly-visible enum has a struct variant whose field is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/enum_struct_variant_field_missing.ron

Failed in:
  field log_fn of variant Config::Cluster, previously in file /tmp/.tmpV5fThF/timely_communication/src/initialize.rs:42
  field log_fn of variant Config::Cluster, previously in file /tmp/.tmpV5fThF/timely_communication/src/initialize.rs:42

--- failure function_parameter_count_changed: pub fn parameter count changed ---

Description:
A publicly-visible function now takes a different number of parameters.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#fn-change-arity
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/function_parameter_count_changed.ron

Failed in:
  timely_communication::allocator::zero_copy::initialize::initialize_networking_from_sockets now takes 5 parameters instead of 6, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/initialize.rs:62
  timely_communication::allocator::zero_copy::initialize::initialize_networking now takes 6 parameters instead of 7, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/initialize.rs:41
  timely_communication::allocator::zero_copy::tcp::send_loop now takes 6 parameters instead of 5, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/zero_copy/tcp.rs:137

--- failure method_parameter_count_changed: pub method parameter count changed ---

Description:
A publicly-visible method now takes a different number of parameters, not counting the receiver (self) parameter.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#fn-change-arity
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/method_parameter_count_changed.ron

Failed in:
  timely_communication::allocator::ProcessBuilder::new_typed_vector now takes 3 parameters instead of 2, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/mod.rs:155
  timely_communication::allocator::ProcessBuilder::new_bytes_vector now takes 3 parameters instead of 2, in /tmp/.tmpgO9Wg7/timely-dataflow/communication/src/allocator/mod.rs:163

Changelog

timely

0.29.0 - 2026-04-13

The theme in this release is simplifying specialization by removing monomorphization sprawl.
The Scope trait that used to have numerous implementors is now a concrete type that only varies with lifetime and timestamp.
Operator closures are boxed by default.
These resulted in a ~25% reduction in LLVM lines in Materialize.

Some forms of specialization have vanished; reach out if you relied on them.
Also, check out the Scope::scoped_raw method for more flexibility in assembling scopes.

Scope is now a lightweight, Copy handle

Scope has been substantially simplified. It is now a concrete Copy type rather than a trait:

pub struct Scope<'scope, T: Timestamp> {
    subgraph: &'scope RefCell<SubgraphBuilder<T>>,
    worker:   &'scope Worker,
}

Previously, Scope was a trait (implemented by Child) and code was generic over G: Scope.
Now Scope is a concrete type parameterized by a lifetime and its timestamp, previously hidden in the G: Scope implementation, and now code uses Scope<'scope, T> directly.

• Scope is a concrete type, not a trait. The Child type is gone. Where you previously had a generic parameter G: Scope or G: Scope<Timestamp = T>, you now use Scope<'scope, T> directly. This means replacing a type-level generic with a lifetime and a concrete timestamp type — you may need to introduce 'scope and T: Timestamp where they weren't needed before, and remove G from your generic parameter lists.
• Scope implements Copy. It is passed by value to dataflow closures and operator constructors. The FnOnce(&Scope<T>) pattern becomes FnOnce(Scope<T>).
• AsWorker and Scheduler traits are removed. Their methods are now inherent on Worker. Access the worker from a scope via scope.worker().
• All Scope methods take &self, not &mut self. Extension traits that took &mut self on Scope (e.g., Input, Feedback, UnorderedInput) now take &self.

Migration guide

Before (0.28)	After (0.29)
G: Scope or G: Scope<Timestamp = T>	Scope<'scope, T>
Child<'scope, _, T>	Scope<'scope, T>
AsWorker::logging(&scope)	scope.worker().logging()
use timely::scheduling::Scheduler;	(remove — methods are inherent on Worker)
FnOnce(&mut Scope<T>)	FnOnce(Scope<T>)
scope: &Scope<'scope, T> in free functions	scope: Scope<'scope, T>

Other

• Box operator logic by default (#786)
• Remove Allocate trait; replace with Allocator. (#778)
• Checks for WASM compatibility (#777)

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This PR was generated with release-plz.