model_sources validation rejects documented format in v1.8.3

[PascalAI2024]

Description

When using kaggle kernels push with model_sources in the documented format username/model-slug/framework/variation-slug/version-number, the CLI rejects it with:

Model must be specified in the form of '{owner}/{model-slug}'

However, the Kernel Metadata documentation states:

A list of model sources, specified as "username/model-slug/framework/variation-slug/version-number"

Steps to Reproduce

1. Create kernel-metadata.json with:

{
  "model_sources": ["manwithacat/byt5-combined/transformers/transformers/1"]
}

2. Run kaggle kernels push

3. Error: Model must be specified in the form of '{owner}/{model-slug}'

Expected Behavior

The CLI should accept the documented format username/model-slug/framework/variation-slug/version-number.

Workaround

Using an older version (1.7.4.5 via pip) accepts the format and correctly attaches the model.

Environment

• Broken: Kaggle API 1.8.3 (homebrew, macOS)
• Working: Kaggle API 1.7.4.5 (pip)
• OS: macOS Darwin 25.2.0

Related

This is distinct from #643 (model_sources ignored) which was fixed. This is a validation regression in newer versions.