Cannot migrate a semantic text index from 8.18 to 9.0

[Mikep86]

Elasticsearch Version

9.0

Installed Plugins

No response

Java Version

bundled

OS Version

N/A

Problem Description

If a user creates an index with a semantic_text field in 8.18+, they cannot migrate that index to 9.0. If they try, they get this error:

"type": "illegal_argument_exception",
        "reason": """cannot change field "description.inference.chunks.embeddings" from storeTermVector=true to inconsistent storeTermVector=false"""

Steps to Reproduce

1. Create an index with a semantic_text field in 8.18
2. Upgrade to 9.0
3. Attempt to reload the index on 9.0

Logs (if relevant)

No response

[elasticsearchmachine]

Pinging @elastic/search-eng (Team:SearchOrg)

[elasticsearchmachine]

Pinging @elastic/search-relevance (Team:Search - Relevance)

[Mikep86]

Fixed by #125446