Source generator diagnostics

Modular Pipelines generates registration metadata at compile time. A generator diagnostic explains why metadata could not be emitted safely and whether the build will fail. Command and secret metadata must be generated for C# types; runtime reflection remains only for assemblies not processed by the C# source generator, including F# and Visual Basic, because those languages cannot run the C# source generator.

MPG0001

An invalid method has [ModularPipelinesIntegration]. The method and its containing type must be accessible and non-generic. The method must be static, accept one IServiceCollection by-value parameter, and return either void or IServiceCollection.

Severity: Error

MPG0002

Two module types produce the same generated accessor name. Rename one module so stripping the Module suffix produces a unique name.

Severity: Error

MPG0003

An inaccessible property, an invalid attribute argument, or conflicting command attributes prevent complete command metadata generation. Make the property and getter accessible, and apply only one of [CliArgument], [CliFlag], or [CliOption] to each property. The build fails until every attributed property can be generated unambiguously.

Severity: Error

MPG0004

An inaccessible property marked with [SecretValue] prevents complete secret metadata generation. Make the property and getter accessible to generated code. The build fails until every attributed property can be generated.

Severity: Error

MPG0005

A module attribute cannot be constructed by generated code. Attribute types, constructors, named members, and referenced argument types must be accessible. Attribute arguments must also be representable as C# literals. Until fixed, Modular Pipelines uses runtime reflection for the missing metadata.

Severity: Warning

MPG0006

Command or secret metadata generation was skipped because its declaring type is generic, inaccessible, file-local, part of a partial type hierarchy, or has the same metadata name as a type in another assembly. Make the type and its containing types accessible and non-generic. Move file-local command or secret types to an accessible declaration, combine partial command/secret declarations into one non-partial declaration, and give colliding types unique metadata names. The build fails because exact generated metadata cannot be guaranteed for these shapes.

The generator reports this diagnostic when it recognizes a command or secret type, or when it observes the type in an Options or dependency-injection usage such as IOptions<T>, Configure<T>, AddOptions<T>, or a service registration. An unrelated type with one of these declaration shapes does not require runtime metadata and does not trigger MPG0006.

Severity: Error

MPG0007

Module event metadata generation was skipped because a concrete module type is generic or inaccessible to generated code. Make the type and its containing types accessible and non-generic. Until fixed, Modular Pipelines uses runtime reflection.

Severity: Info

MPG0008

A tool accessor cannot generate a discoverable context.Tools property because the consuming project uses a language version older than C# 14. Registration metadata still generates. Use C# 14 or preview to enable the property, or use the diagnostic's context.X() compatibility accessor.

Severity: Warning

MPG0009

Multiple tool accessors would generate the same discoverable property with conflicting declarations. Give each accessor a unique name.

Severity: Error

MPG0010

A tool accessor would generate a property whose name is already available on IToolsContext or object, such as Get or GetType. Rename the accessor.

Severity: Error

MPG0011

Module runtime metadata generation was skipped because the module or one of its containing types is inaccessible to generated code. Make the module and its containing types accessible before publishing with Native AOT. Runtime reflection remains available for ordinary JIT deployments.

Severity: Warning

MPG0012

A consumer references a closed generic module declared in another assembly, either through AddModule<T>() or a transitive DependsOn<T> chain. The consumer generator cannot add runtime metadata owned by that external assembly. Use a consumer-owned non-generic wrapper for the module before publishing with Native AOT.

Severity: Warning

MPG0013

An AddModule<TModule>() call uses a type parameter. The source generator cannot determine every closed construction that may flow through the generic helper, so trim-safe runtime metadata cannot be generated. Register each concrete module type directly, or use a non-generic helper that lists concrete registrations explicitly, before publishing with Native AOT.

Severity: Warning

MPG0014

A module has one or more partial declarations. Another source generator can add a partial declaration that this generator cannot observe, so dependency metadata remains incomplete and runtime reflection is used as a fallback. Avoid partial module declarations before publishing with Native AOT.

Severity: Warning

MPG0015

An AddModule call uses a non-concrete static module type, such as IModule or an abstract module base class. The source generator cannot determine the concrete runtime type, so trim-safe runtime metadata cannot be generated. Register the concrete module type directly before publishing with Native AOT.

Severity: Warning

MPG0016

A module, base class, or implemented interface uses dependency metadata that requires runtime reflection. This includes DependsOnAllModulesInheritingFrom<T>, DependsOnModulesWithTag, DependsOnModulesInCategory, DependsOnModulesWithAttribute<T>, a custom DependsOnBaseAttribute, or a custom DependsOnAttribute subclass. Trimming can remove this metadata. Replace it with the built-in explicit DependsOn<T> attribute before publishing with Native AOT.

Severity: Warning

MPG0017

A type registered through the options dependency-injection APIs was emitted by another source generator in the same compilation. Source generators cannot observe one another's output, so trim-safe runtime metadata cannot be generated. Declare the type in user source or a referenced assembly before publishing with trimming or Native AOT.

Severity: Error

Diagnostics can be configured with standard MSBuild or .editorconfig settings. For example:

dotnet_diagnostic.MPG0003.severity = error