#10303 feat: suggest existing locked variants when plugin definition is not found Pull request opened by BLVCK-MAMBA-6 Description When a plugin definition fails to resolve because no variant was explicitly specified in

meltano.yml

, Meltano previously surfaced a generic error directing users to run

meltano lock --update --all

. If a lockfile already exists on disk for that plugin under a specific variant (e.g.,

tap-fleetio--fleetio.lock

), this PR detects it and surfaces an actionable error message that: • Explains which variant lockfile(s) exist on disk. • Instructs the user to add

variant: <variant_name>

to their plugin definition in

meltano.yml

. Changes • Added

find_locked_variants

to

PluginLockService

and

LockedDefinitionService

to scan for

<plugin_name>--<variant>.lock

files in the plugin root directory. • Updated

PluginDefinitionNotFoundError

to accept discovered variants and generate a contextual reason and remediation instruction. • Added regression test

test_plugin_definition_not_found_suggests_variant

in

tests/meltano/core/test_project_plugins_service.py

. Verification • Ran test module:

uv run pytest tests/meltano/core/test_project_plugins_service.py

(10 passed). • Linted and formatted:

uv run --with ruff ruff check

and

ruff format

passed with 0 errors. Checklist • I have read the contribution guide Was generative AI tooling used to co-author this PR? • Yes (Gemini-3.8-flash) Generated-by: Gemini following the agentic coding guidelines Related Issues • Closes #8427 Summary by Sourcery Help users resolve missing plugin definitions by identifying matching locked variants and explaining how to configure them. New Features: • Suggest existing locked plugin variants and the required

variant

configuration when a plugin definition cannot be resolved. Enhancements: • Improve plugin definition errors with contextual explanations and actionable remediation based on discovered lockfiles. • Add resilient locked-variant discovery across plugin lock directories, including handling missing directories and filesystem errors. Tests: • Add regression coverage for single- and multiple-variant suggestions and locked-variant discovery edge cases. meltano/meltano