Can I let an asset A yield a MaterializeResult for a source asset S? When I try this, I get an error saying the asset key for S is not found in the AssetsDefinition.

Based on the documentation, there is no direct mention of yielding a

MaterializeResult

for a source asset. However, the documentation does discuss the use of

AssetMaterialization

within an op to indicate that an asset has been materialized. Typically, an

AssetMaterialization

is yielded to signal that an asset has been materialized and to provide additional metadata about the materialization. If you are encountering an error stating that the asset key for the source asset S is not found in the

AssetsDefinition

, it suggests that there might be a mismatch or an issue with how the source asset is defined or referenced within your asset dependencies. To address this issue, you should ensure that the source asset S is correctly defined and included in the

AssetsDefinition

. If S is a source asset, it should be defined using

SourceAsset

and included in the asset graph. Additionally, when referencing source assets, you should use the correct asset keys and ensure that they match the keys used in the

AssetsDefinition

. If you continue to face issues, it would be helpful to review the exact error message and the code that is causing the issue. This would allow for a more specific diagnosis and guidance on how to resolve the problem. If the documentation does not provide a clear solution, you may need to consult the Dagster community or support channels for further assistance.