chore: release v0.21.0 (#2303)

This release includes a long list of changes:

- The HUGR model serialization format is now stable, and should be
preferred over the old JSON format.
- Type parameters and type arguments are now unified into a single
`Term` type.
- Function definitions can no longer be nested inside dataflow regions.
Now they must be defined at the top level module.
- Function definitions and declarations now have a `Visibility` field,
which define whether they are visible in the public API of the module.
- And many more fixes and improvements.

---

## 🤖 New release

* `hugr-model`: 0.20.2 -> 0.21.0 (⚠ API breaking changes)
* `hugr-core`: 0.20.2 -> 0.21.0 (⚠ API breaking changes)
* `hugr-llvm`: 0.20.2 -> 0.21.0 (⚠ API breaking changes)
* `hugr-passes`: 0.20.2 -> 0.21.0 (✓ API compatible changes)
* `hugr`: 0.20.2 -> 0.21.0 (✓ API compatible changes)
* `hugr-cli`: 0.20.2 -> 0.21.0 (⚠ API breaking changes)

### ⚠ `hugr-model` breaking changes

```text
--- failure constructible_struct_adds_field: externally-constructible struct adds field ---

Description:
A pub struct constructible with a struct literal has a new pub field. Existing struct literals must be updated to include the new field.
        ref: https://doc.rust-lang.org/reference/expressions/struct-expr.html
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/constructible_struct_adds_field.ron

Failed in:
  field Symbol.visibility in /tmp/.tmpEqPTGR/hugr/hugr-model/src/v0/ast/mod.rs:198
  field Symbol.visibility in /tmp/.tmpEqPTGR/hugr/hugr-model/src/v0/table/mod.rs:307

--- failure pub_module_level_const_missing: pub module-level const is missing ---

Description:
A public const is missing or renamed
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/pub_module_level_const_missing.ron

Failed in:
  CORE_CTRL_TYPE in file /tmp/.tmp1p6e1v/hugr-model/src/v0/mod.rs:175

--- failure struct_with_no_pub_fields_changed_type: public API struct with no public fields is no longer a struct ---

Description:
A struct without pub fields became an enum or union, breaking pattern matching.
        ref: https://internals.rust-lang.org/t/rest-patterns-foo-should-match-non-struct-types/21607
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/struct_with_no_pub_fields_changed_type.ron

Failed in:
  struct hugr_model::v0::scope::UnknownVarError became enum in file /tmp/.tmpEqPTGR/hugr/hugr-model/src/v0/scope/vars.rs:147
```

### ⚠ `hugr-core` breaking changes

```text
--- 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/v0.41.0/src/lints/auto_trait_impl_removed.ron

Failed in:
  type Term is no longer UnwindSafe, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/types/type_param.rs:70
  type Term is no longer RefUnwindSafe, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/types/type_param.rs:70

--- failure enum_missing: pub enum removed or renamed ---

Description:
A publicly-visible enum cannot be imported by its prior path. A `pub use` may have been removed, or the enum itself 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/v0.41.0/src/lints/enum_missing.ron

Failed in:
  enum hugr_core::types::type_param::TypeArgError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:450
  enum hugr_core::hugr::persistent::walker::PinNodeError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker.rs:333
  enum hugr_core::hugr::persistent::serial::SerialCommitData, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/state_space/serial.rs:11
  enum hugr_core::import::ImportError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/import.rs:39
  enum hugr_core::import::OrderHintError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/import.rs:82
  enum hugr_core::hugr::persistent::InvalidCommit, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/state_space.rs:474

--- failure enum_no_repr_variant_discriminant_changed: enum variant had its discriminant change value ---

Description:
The enum's variant had its discriminant value change. This breaks downstream code that used its value via a numeric cast like `as isize`.
        ref: https://doc.rust-lang.org/reference/items/enumerations.html#assigning-discriminant-values
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/enum_no_repr_variant_discriminant_changed.ron

Failed in:
  variant InterGraphEdgeError::NonCFGAncestor 2 -> 1 in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/validate.rs:795
  variant InterGraphEdgeError::MissingOrderEdge 3 -> 2 in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/validate.rs:806
  variant InterGraphEdgeError::NoRelation 4 -> 3 in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/validate.rs:817
  variant InterGraphEdgeError::NonDominatedAncestor 5 -> 4 in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/validate.rs:827

--- failure enum_variant_added: enum variant added on exhaustive enum ---

Description:
A publicly-visible enum without #[non_exhaustive] has a new variant.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#enum-variant-new
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/enum_variant_added.ron

Failed in:
  variant TypeBound:Linear in /tmp/.tmpEqPTGR/hugr/hugr-core/src/types.rs:138

--- failure enum_variant_missing: pub enum variant removed or renamed ---

Description:
A publicly-visible enum has at least one variant that 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/v0.41.0/src/lints/enum_variant_missing.ron

Failed in:
  variant PackageEncodingError::RuntimeExtensionResolution, previously in file /tmp/.tmp1p6e1v/hugr-core/src/envelope/package_json.rs:77
  variant Term::Type, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:67
  variant Term::Type, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:158
  variant Term::Sequence, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:180
  variant Term::Type, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:158
  variant Term::Sequence, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:180
  variant TypeBound::Any, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types.rs:136
  variant InterGraphEdgeError::ValueEdgeIntoFunc, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/validate.rs:766
  variant ValidationError::ExtensionError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/validate.rs:714
  variant ValidationError::ExtensionError, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/validate.rs:714

--- failure function_missing: pub fn removed or renamed ---

Description:
A publicly-visible function cannot be imported by its prior path. A `pub use` may have been removed, or the function itself 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/v0.41.0/src/lints/function_missing.ron

Failed in:
  function hugr_core::types::type_param::check_type_arg, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:384
  function hugr_core::types::type_param::check_type_args, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:437

--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn 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/v0.41.0/src/lints/inherent_method_missing.ron

Failed in:
  Term::max_nat, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:100
  Term::bounded_nat, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:108
  Term::as_type, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:275
  Term::as_type, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:275

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

Description:
A publicly-visible method 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/v0.41.0/src/lints/method_parameter_count_changed.ron

Failed in:
  hugr_core::hugr::patch::simple_replace::SimpleReplacement::linked_replacement_output now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:134
  hugr_core::hugr::patch::simple_replace::SimpleReplacement::linked_replacement_inputs now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:221
  hugr_core::hugr::patch::SimpleReplacement::linked_replacement_output now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:134
  hugr_core::hugr::patch::SimpleReplacement::linked_replacement_inputs now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:221
  hugr_core::hugr::SimpleReplacement::linked_replacement_output now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:134
  hugr_core::hugr::SimpleReplacement::linked_replacement_inputs now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:221
  hugr_core::SimpleReplacement::linked_replacement_output now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:134
  hugr_core::SimpleReplacement::linked_replacement_inputs now takes 4 parameters instead of 3, in /tmp/.tmpEqPTGR/hugr/hugr-core/src/hugr/patch/simple_replace.rs:221

--- failure module_missing: pub module removed or renamed ---

Description:
A publicly-visible module cannot be imported by its prior path. A `pub use` may have been removed, or the module may have been renamed, removed, or made non-public.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/module_missing.ron

Failed in:
  mod hugr_core::hugr::persistent, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent.rs:1
  mod hugr_core::hugr::persistent::walker, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker.rs:1
  mod hugr_core::hugr::persistent::serial, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent.rs:769

--- failure struct_missing: pub struct removed or renamed ---

Description:
A publicly-visible struct cannot be imported by its prior path. A `pub use` may have been removed, or the struct itself 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/v0.41.0/src/lints/struct_missing.ron

Failed in:
  struct hugr_core::hugr::persistent::PatchNode, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/state_space.rs:28
  struct hugr_core::hugr::persistent::walker::PinnedWire, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker/pinned.rs:30
  struct hugr_core::hugr::persistent::PinnedWire, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker/pinned.rs:30
  struct hugr_core::hugr::persistent::PersistentHugr, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent.rs:274
  struct hugr_core::hugr::persistent::serial::SerialCommitStateSpace, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/state_space/serial.rs:54
  struct hugr_core::types::type_param::TypeArgVariable, previously in file /tmp/.tmp1p6e1v/hugr-core/src/types/type_param.rs:236
  struct hugr_core::hugr::persistent::walker::Walker, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker.rs:87
  struct hugr_core::hugr::persistent::Walker, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/walker.rs:87
  struct hugr_core::hugr::persistent::PointerEqResolver, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/resolver.rs:11
  struct hugr_core::hugr::persistent::CommitStateSpace, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent/state_space.rs:64
  struct hugr_core::hugr::persistent::Commit, previously in file /tmp/.tmp1p6e1v/hugr-core/src/hugr/persistent.rs:108

--- failure trait_method_missing: pub trait method removed or renamed ---

Description:
A trait method is no longer callable, and may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#major-any-change-to-trait-item-signatures
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/trait_method_missing.ron

Failed in:
  method define_function of trait Container, previously in file /tmp/.tmp1p6e1v/hugr-core/src/builder/build_traits.rs:92
```

### ⚠ `hugr-llvm` breaking changes

```text
--- failure trait_method_requires_different_generic_type_params: trait method now requires a different number of generic type parameters ---

Description:
A trait method now requires a different number of generic type parameters than it used to. Calls or implementations of this trait method using the previous number of generic types will be broken.
        ref: https://doc.rust-lang.org/reference/items/generics.html
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.41.0/src/lints/trait_method_requires_different_generic_type_params.ron

Failed in:
  FatExt::fat_root (1 -> 0 generic types) in /tmp/.tmpEqPTGR/hugr/hugr-llvm/src/utils/fat.rs:376
```

### ⚠ `hugr-cli` breaking changes

```text
--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn 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/v0.41.0/src/lints/inherent_method_missing.ron

Failed in:
  ValArgs::verbosity, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/validate.rs:53
  MermaidArgs::verbosity, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/mermaid.rs:78

--- failure struct_pub_field_missing: pub struct's pub field removed or renamed ---

Description:
A publicly-visible struct has at least one public field that 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/v0.41.0/src/lints/struct_pub_field_missing.ron

Failed in:
  field other_args of struct ValArgs, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/validate.rs:24
  field other_args of struct MermaidArgs, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/mermaid.rs:36

--- warning enum_missing: pub enum removed or renamed ---

Description:
A publicly-visible enum cannot be imported by its prior path. A `pub use` may have been removed, or the enum itself 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/v0.41.0/src/lints/enum_missing.ron

Failed in:
  enum hugr_cli::CliArgs, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/lib.rs:78

--- warning struct_missing: pub struct removed or renamed ---

Description:
A publicly-visible struct cannot be imported by its prior path. A `pub use` may have been removed, or the struct itself 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/v0.41.0/src/lints/struct_missing.ron

Failed in:
  struct hugr_cli::OtherArgs, previously in file /tmp/.tmp1p6e1v/hugr-cli/src/lib.rs:122
```

<details><summary><i><b>Changelog</b></i></summary><p>

## `hugr-model`

<blockquote>

##
[0.21.0](hugr-model-v0.20.2...hugr-model-v0.21.0)
- 2025-07-09

### Bug Fixes

- Model import should perform extension resolution
([#2326](#2326))
- [**breaking**] Fixed bugs in model CFG handling and improved CFG
signatures ([#2334](#2334))
- [**breaking**] Fix panic in model resolver when variable is used
outside of symbol. ([#2362](#2362))
- Order hints on input and output nodes.
([#2422](#2422))

### New Features

- [**breaking**] Added float and bytes literal to core and python
bindings. ([#2289](#2289))
- better errors using metadata from generator
([#2368](#2368))
- [**breaking**] Add Visibility to FuncDefn/FuncDecl.
([#2143](#2143))
- [**breaking**] hugr-model use explicit Option<Visibility>, with
::Unspecified in capnp ([#2424](#2424))
</blockquote>

## `hugr-core`

<blockquote>

##
[0.21.0](hugr-core-v0.20.2...hugr-core-v0.21.0)
- 2025-07-09

### Bug Fixes

- Fixed two bugs in import/export of function operations
([#2324](#2324))
- Model import should perform extension resolution
([#2326](#2326))
- [**breaking**] Fixed bugs in model CFG handling and improved CFG
signatures ([#2334](#2334))
- Use List instead of Tuple in conversions for TypeArg/TypeRow
([#2378](#2378))
- Do extension resolution on loaded extensions from the model format
([#2389](#2389))
- Make JSON Schema checks actually work again
([#2412](#2412))
- Order hints on input and output nodes.
([#2422](#2422))

### New Features

- [**breaking**] No nested FuncDefns (or AliasDefns)
([#2256](#2256))
- Add serial data types for SimpleReplacement and PersistentHugr
([#2300](#2300))
- [**breaking**] Split `TypeArg::Sequence` into tuples and lists.
([#2140](#2140))
- [**breaking**] Added float and bytes literal to core and python
bindings. ([#2289](#2289))
- [**breaking**] More helpful error messages in model import
([#2272](#2272))
- Add MermaidFormatter to replace RenderConfig
([#2275](#2275))
- [**breaking**] Better error reporting in `hugr-cli`.
([#2318](#2318))
- *(core)* builder pattern for EnvelopeConfig
([#2330](#2330))
- *(core, llvm)* add array unpack operations
([#2339](#2339))
- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in
Rust ([#2309](#2309))
- *(persistent)* Add serialisation for CommitStateSpace
([#2344](#2344))
- Deprecate invalidation_set, add invalidated_nodes and
SimpleReplacement::invalidation_set
([#2358](#2358))
- Rewrite for peeling a TailLoop
([#2290](#2290))
- Create Module/FunctionBuilders from existing Hugrs
([#2359](#2359))
- add TryFrom impls for TypeArg/TypeRow
([#2366](#2366))
- better errors using metadata from generator
([#2368](#2368))
- use `core.` prefixes for generator metadata keys
([#2371](#2371))
- Add `MakeError` op ([#2377](#2377))
- Open lists and tuples in `Term`
([#2360](#2360))
- Call `FunctionBuilder::add_{in,out}put` for any AsMut<Hugr>
([#2376](#2376))
- Add Root checked methods to DataflowParentID
([#2382](#2382))
- Add PersistentWire type
([#2361](#2361))
- Add `BorrowArray` extension
([#2395](#2395))
- [**breaking**] Rename 'Any' type bound to 'Linear'
([#2421](#2421))
- [**breaking**] Add Visibility to FuncDefn/FuncDecl.
([#2143](#2143))
- *(per)* [**breaking**] Support empty wires in commits
([#2349](#2349))
- [**breaking**] hugr-model use explicit Option<Visibility>, with
::Unspecified in capnp ([#2424](#2424))

### Refactor

- [**breaking**] move PersistentHugr into separate crate
([#2277](#2277))
- *(types.rs)* rm incorrect comment and unnecessary allow-unused
([#2340](#2340))
- [**breaking**] remove deprecated runtime extension errors
([#2369](#2369))
- [**breaking**] Reduce error type sizes
([#2420](#2420))

### Testing

- Check hugr json serializations against the schema (again)
([#2216](#2216))
</blockquote>

## `hugr-llvm`

<blockquote>

##
[0.21.0](hugr-llvm-v0.20.2...hugr-llvm-v0.21.0)
- 2025-07-09

### New Features

- [**breaking**] No nested FuncDefns (or AliasDefns)
([#2256](#2256))
- [**breaking**] Split `TypeArg::Sequence` into tuples and lists.
([#2140](#2140))
- [**breaking**] More helpful error messages in model import
([#2272](#2272))
- *(core, llvm)* add array unpack operations
([#2339](#2339))
- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in
Rust ([#2309](#2309))
- Add `MakeError` op ([#2377](#2377))

### Refactor

- *(llvm)* replace HashMap with BTreeMap
([#2313](#2313))
</blockquote>

## `hugr-passes`

<blockquote>

##
[0.21.0](hugr-passes-v0.20.2...hugr-passes-v0.21.0)
- 2025-07-09

### Bug Fixes

- update CallGraph and remove_dead_funcs for module-only FuncDefns
([#2336](#2336))
- DeadFuncElimPass+CallGraph w/ non-module-child entrypoint
([#2390](#2390))

### New Features

- [**breaking**] No nested FuncDefns (or AliasDefns)
([#2256](#2256))
- [**breaking**] Split `TypeArg::Sequence` into tuples and lists.
([#2140](#2140))
- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in
Rust ([#2309](#2309))
- [**breaking**] Rename 'Any' type bound to 'Linear'
([#2421](#2421))

### Refactor

- [**breaking**] Reduce error type sizes
([#2420](#2420))
</blockquote>

## `hugr`

<blockquote>

##
[0.21.0](hugr-v0.20.2...hugr-v0.21.0)
- 2025-07-09

### Bug Fixes

- update CallGraph and remove_dead_funcs for module-only FuncDefns
([#2336](#2336))
- DeadFuncElimPass+CallGraph w/ non-module-child entrypoint
([#2390](#2390))
- Fixed two bugs in import/export of function operations
([#2324](#2324))
- Model import should perform extension resolution
([#2326](#2326))
- [**breaking**] Fixed bugs in model CFG handling and improved CFG
signatures ([#2334](#2334))
- Use List instead of Tuple in conversions for TypeArg/TypeRow
([#2378](#2378))
- Do extension resolution on loaded extensions from the model format
([#2389](#2389))
- Make JSON Schema checks actually work again
([#2412](#2412))
- Order hints on input and output nodes.
([#2422](#2422))

### Documentation

- Hide hugr-persistent docs
([#2357](#2357))

### New Features

- Add serial data types for SimpleReplacement and PersistentHugr
([#2300](#2300))
- [**breaking**] Split `TypeArg::Sequence` into tuples and lists.
([#2140](#2140))
- [**breaking**] Added float and bytes literal to core and python
bindings. ([#2289](#2289))
- [**breaking**] More helpful error messages in model import
([#2272](#2272))
- Add MermaidFormatter to replace RenderConfig
([#2275](#2275))
- [**breaking**] Better error reporting in `hugr-cli`.
([#2318](#2318))
- *(core, llvm)* add array unpack operations
([#2339](#2339))
- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in
Rust ([#2309](#2309))
- *(persistent)* Add serialisation for CommitStateSpace
([#2344](#2344))
- Deprecate invalidation_set, add invalidated_nodes and
SimpleReplacement::invalidation_set
([#2358](#2358))
- Rewrite for peeling a TailLoop
([#2290](#2290))
- Create Module/FunctionBuilders from existing Hugrs
([#2359](#2359))
- add TryFrom impls for TypeArg/TypeRow
([#2366](#2366))
- better errors using metadata from generator
([#2368](#2368))
- use `core.` prefixes for generator metadata keys
([#2371](#2371))
- Add `MakeError` op ([#2377](#2377))
- Open lists and tuples in `Term`
([#2360](#2360))
- Call `FunctionBuilder::add_{in,out}put` for any AsMut<Hugr>
([#2376](#2376))
- Add Root checked methods to DataflowParentID
([#2382](#2382))
- Add PersistentWire type
([#2361](#2361))
- Add `BorrowArray` extension
([#2395](#2395))
- [**breaking**] Add Visibility to FuncDefn/FuncDecl.
([#2143](#2143))
- *(per)* [**breaking**] Support empty wires in commits
([#2349](#2349))
- [**breaking**] hugr-model use explicit Option<Visibility>, with
::Unspecified in capnp ([#2424](#2424))
- [**breaking**] No nested FuncDefns (or AliasDefns)
([#2256](#2256))
- *(core)* builder pattern for EnvelopeConfig
([#2330](#2330))
- [**breaking**] Rename 'Any' type bound to 'Linear'
([#2421](#2421))

### Refactor

- *(types.rs)* rm incorrect comment and unnecessary allow-unused
([#2340](#2340))
- [**breaking**] remove deprecated runtime extension errors
([#2369](#2369))
- [**breaking**] Reduce error type sizes
([#2420](#2420))
- [**breaking**] move PersistentHugr into separate crate
([#2277](#2277))

### Testing

- Check hugr json serializations against the schema (again)
([#2216](#2216))
</blockquote>

## `hugr-cli`

<blockquote>

##
[0.21.0](hugr-cli-v0.20.2...hugr-cli-v0.21.0)
- 2025-07-09

### New Features

- [**breaking**] Better error reporting in `hugr-cli`.
([#2318](#2318))
- *(cli)* convert sub-command for converting envelope formats
([#2331](#2331))
</blockquote>


</p></details>

---
This PR was generated with
[release-plz](https://github.com/release-plz/release-plz/).

---------

Co-authored-by: Agustín Borgna <agustin.borgna@quantinuum.com>

Author: hugrbot

Cargo.lock

@@ -1,6 +1,12 @@
 # Changelog
 
 
+## [0.21.0](https://github.com/CQCL/hugr/compare/hugr-cli-v0.20.2...hugr-cli-v0.21.0) - 2025-07-09
+
+### New Features
+
+- [**breaking**] Better error reporting in `hugr-cli`. ([#2318](https://github.com/CQCL/hugr/pull/2318))
+
 ## [0.20.2](https://github.com/CQCL/hugr/compare/hugr-cli-v0.20.1...hugr-cli-v0.20.2) - 2025-06-25
 
 ### New Features

hugr-cli/CHANGELOG.md

@@ -1,6 +1,6 @@
 [package]
 name = "hugr-cli"
-version = "0.20.2"
+version = "0.21.0"
 edition = { workspace = true }
 rust-version = { workspace = true }
 license = { workspace = true }
@@ -19,7 +19,7 @@ bench = false
 clap = { workspace = true, features = ["derive", "cargo"] }
 clap-verbosity-flag.workspace = true
 derive_more = { workspace = true, features = ["display", "error", "from"] }
-hugr = { path = "../hugr", version = "0.20.2" }
+hugr = { path = "../hugr", version = "0.21.0" }
 serde_json.workspace = true
 clio = { workspace = true, features = ["clap-parse"] }
 anyhow.workspace = true

hugr-cli/Cargo.toml

@@ -1,5 +1,48 @@
 # Changelog
 
+## [0.21.0](https://github.com/CQCL/hugr/compare/hugr-core-v0.20.2...hugr-core-v0.21.0) - 2025-07-09
+
+### Bug Fixes
+
+- Fixed two bugs in import/export of function operations ([#2324](https://github.com/CQCL/hugr/pull/2324))
+- Model import should perform extension resolution ([#2326](https://github.com/CQCL/hugr/pull/2326))
+- [**breaking**] Fixed bugs in model CFG handling and improved CFG signatures ([#2334](https://github.com/CQCL/hugr/pull/2334))
+- Use List instead of Tuple in conversions for TypeArg/TypeRow ([#2378](https://github.com/CQCL/hugr/pull/2378))
+- Do extension resolution on loaded extensions from the model format ([#2389](https://github.com/CQCL/hugr/pull/2389))
+- Make JSON Schema checks actually work again ([#2412](https://github.com/CQCL/hugr/pull/2412))
+- Order hints on input and output nodes. ([#2422](https://github.com/CQCL/hugr/pull/2422))
+
+### New Features
+
+- [**breaking**] No nested FuncDefns (or AliasDefns) ([#2256](https://github.com/CQCL/hugr/pull/2256))
+- [**breaking**] Split `TypeArg::Sequence` into tuples and lists. ([#2140](https://github.com/CQCL/hugr/pull/2140))
+- [**breaking**] Added float and bytes literal to core and python bindings. ([#2289](https://github.com/CQCL/hugr/pull/2289))
+- [**breaking**] More helpful error messages in model import ([#2272](https://github.com/CQCL/hugr/pull/2272))
+- [**breaking**] Better error reporting in `hugr-cli`. ([#2318](https://github.com/CQCL/hugr/pull/2318))
+- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in Rust ([#2309](https://github.com/CQCL/hugr/pull/2309))
+- *(persistent)* Add serialisation for CommitStateSpace ([#2344](https://github.com/CQCL/hugr/pull/2344))
+- add TryFrom impls for TypeArg/TypeRow ([#2366](https://github.com/CQCL/hugr/pull/2366))
+- Add `MakeError` op ([#2377](https://github.com/CQCL/hugr/pull/2377))
+- Open lists and tuples in `Term` ([#2360](https://github.com/CQCL/hugr/pull/2360))
+- Call `FunctionBuilder::add_{in,out}put` for any AsMut<Hugr> ([#2376](https://github.com/CQCL/hugr/pull/2376))
+- Add Root checked methods to DataflowParentID ([#2382](https://github.com/CQCL/hugr/pull/2382))
+- Add PersistentWire type ([#2361](https://github.com/CQCL/hugr/pull/2361))
+- Add `BorrowArray` extension ([#2395](https://github.com/CQCL/hugr/pull/2395))
+- [**breaking**] Rename 'Any' type bound to 'Linear' ([#2421](https://github.com/CQCL/hugr/pull/2421))
+- [**breaking**] Add Visibility to FuncDefn/FuncDecl. ([#2143](https://github.com/CQCL/hugr/pull/2143))
+- *(per)* [**breaking**] Support empty wires in commits ([#2349](https://github.com/CQCL/hugr/pull/2349))
+- [**breaking**] hugr-model use explicit Option<Visibility>, with ::Unspecified in capnp ([#2424](https://github.com/CQCL/hugr/pull/2424))
+
+### Refactor
+
+- [**breaking**] move PersistentHugr into separate crate ([#2277](https://github.com/CQCL/hugr/pull/2277))
+- [**breaking**] remove deprecated runtime extension errors ([#2369](https://github.com/CQCL/hugr/pull/2369))
+- [**breaking**] Reduce error type sizes ([#2420](https://github.com/CQCL/hugr/pull/2420))
+
+### Testing
+
+- Check hugr json serializations against the schema (again) ([#2216](https://github.com/CQCL/hugr/pull/2216))
+
 ## [0.20.2](https://github.com/CQCL/hugr/compare/hugr-core-v0.20.1...hugr-core-v0.20.2) - 2025-06-25
 
 ### Documentation

hugr-core/CHANGELOG.md

@@ -1,6 +1,6 @@
 [package]
 name = "hugr-core"
-version = "0.20.2"
+version = "0.21.0"
 edition = { workspace = true }
 rust-version = { workspace = true }
 
@@ -28,7 +28,7 @@ bench = false
 name = "model"
 
 [dependencies]
-hugr-model = { version = "0.20.2", path = "../hugr-model" }
+hugr-model = { version = "0.21.0", path = "../hugr-model" }
 
 cgmath = { workspace = true, features = ["serde"] }
 delegate = { workspace = true }

hugr-core/Cargo.toml

@@ -5,6 +5,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [0.21.0](https://github.com/CQCL/hugr/compare/hugr-llvm-v0.20.2...hugr-llvm-v0.21.0) - 2025-07-09
+
+### New Features
+
+- [**breaking**] No nested FuncDefns (or AliasDefns) ([#2256](https://github.com/CQCL/hugr/pull/2256))
+- [**breaking**] Split `TypeArg::Sequence` into tuples and lists. ([#2140](https://github.com/CQCL/hugr/pull/2140))
+- [**breaking**] More helpful error messages in model import ([#2272](https://github.com/CQCL/hugr/pull/2272))
+- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in Rust ([#2309](https://github.com/CQCL/hugr/pull/2309))
+- Add `MakeError` op ([#2377](https://github.com/CQCL/hugr/pull/2377))
+
 ## [0.20.2](https://github.com/CQCL/hugr/compare/hugr-llvm-v0.20.1...hugr-llvm-v0.20.2) - 2025-06-25
 
 ### New Features

hugr-llvm/CHANGELOG.md

@@ -1,6 +1,6 @@
 [package]
 name = "hugr-llvm"
-version = "0.20.2"
+version = "0.21.0"
 description = "A general and extensible crate for lowering HUGRs into LLVM IR"
 
 edition.workspace = true
@@ -26,7 +26,7 @@ workspace = true
 
 [dependencies]
 inkwell = { version = "0.6.0", default-features = false }
-hugr-core = { path = "../hugr-core", version = "0.20.1" }
+hugr-core = { path = "../hugr-core", version = "0.21.0" }
 anyhow.workspace = true
 itertools.workspace = true
 delegate.workspace = true

hugr-llvm/Cargo.toml

@@ -1,5 +1,20 @@
 # Changelog
 
+## [0.21.0](https://github.com/CQCL/hugr/compare/hugr-model-v0.20.2...hugr-model-v0.21.0) - 2025-07-09
+
+### Bug Fixes
+
+- Model import should perform extension resolution ([#2326](https://github.com/CQCL/hugr/pull/2326))
+- [**breaking**] Fixed bugs in model CFG handling and improved CFG signatures ([#2334](https://github.com/CQCL/hugr/pull/2334))
+- [**breaking**] Fix panic in model resolver when variable is used outside of symbol. ([#2362](https://github.com/CQCL/hugr/pull/2362))
+- Order hints on input and output nodes. ([#2422](https://github.com/CQCL/hugr/pull/2422))
+
+### New Features
+
+- [**breaking**] Added float and bytes literal to core and python bindings. ([#2289](https://github.com/CQCL/hugr/pull/2289))
+- [**breaking**] Add Visibility to FuncDefn/FuncDecl. ([#2143](https://github.com/CQCL/hugr/pull/2143))
+- [**breaking**] hugr-model use explicit Option<Visibility>, with ::Unspecified in capnp ([#2424](https://github.com/CQCL/hugr/pull/2424))
+
 ## [0.20.2](https://github.com/CQCL/hugr/compare/hugr-model-v0.20.1...hugr-model-v0.20.2) - 2025-06-25
 
 ### New Features

hugr-model/CHANGELOG.md

@@ -1,6 +1,6 @@
 [package]
 name = "hugr-model"
-version = "0.20.2"
+version = "0.21.0"
 readme = "README.md"
 documentation = "https://docs.rs/hugr-model/"
 description = "Data model for Quantinuum's HUGR intermediate representation"

hugr-model/Cargo.toml

@@ -1,6 +1,23 @@
 # Changelog
 
 
+## [0.21.0](https://github.com/CQCL/hugr/compare/hugr-passes-v0.20.2...hugr-passes-v0.21.0) - 2025-07-09
+
+### Bug Fixes
+
+- DeadFuncElimPass+CallGraph w/ non-module-child entrypoint ([#2390](https://github.com/CQCL/hugr/pull/2390))
+
+### New Features
+
+- [**breaking**] No nested FuncDefns (or AliasDefns) ([#2256](https://github.com/CQCL/hugr/pull/2256))
+- [**breaking**] Split `TypeArg::Sequence` into tuples and lists. ([#2140](https://github.com/CQCL/hugr/pull/2140))
+- [**breaking**] Merge `TypeParam` and `TypeArg` into one `Term` type in Rust ([#2309](https://github.com/CQCL/hugr/pull/2309))
+- [**breaking**] Rename 'Any' type bound to 'Linear' ([#2421](https://github.com/CQCL/hugr/pull/2421))
+
+### Refactor
+
+- [**breaking**] Reduce error type sizes ([#2420](https://github.com/CQCL/hugr/pull/2420))
+
 ## [0.20.2](https://github.com/CQCL/hugr/compare/hugr-passes-v0.20.1...hugr-passes-v0.20.2) - 2025-06-25
 
 ### Bug Fixes