Remove installed (third-party) packages from search order for materialization macros

[MichelleArk]

Housekeeping

• I am a maintainer of dbt-core

Short description

Materializations defined in third-party packages are included in the search order for materialization macros. This is difficult to detect, difficult to prevent, and it works differently from other macros.

We should remove third-party packages from the search order.

This change needs to go behind a behavior-change flag:Legacy behaviors | dbt Developer Hub . See Feature/source freshness hooks by MichelleArk · Pull Request #9366 · dbt-labs/dbt-core for an implementation of a behavior-change flag.

Acceptance criteria

Materializations defined in packages are not used. Only materializations defined in the root project or dbt namespace (dbt adapters) appear in the search order.

Suggested Tests

tests for adapter & root overrides of built-in materializations with the legacy flag set to True/False

Impact to Other Teams

N/A

Will backports be required?

1.6, 1.7

Context

No response

[FishtownBuildBot]

Opened a new issue in dbt-labs/docs.getdbt.com: dbt-labs/docs.getdbt.com#5334

[haritamar]

@jtcohen6 @MichelleArk - to clarify, will the require_explicit_package_overrides_for_builtin_materializations keep being available in future versions, or do you intend to deprecate it as well?

[jtcohen6]

@haritamar We don't have any immediate plans to remove that flag. If we did, the very earliest possible would be in v1.10 (2025).

For the foreseeable future, and certainly in v1.8, users will continue to be able to set the flag to False. If they set it to False, they will continue to see the deprecation warnings, however. It's not intended to be a long-term resolution, just a migration path that decouples the behavior change from the dbt-core version they're using.