How to reproduce:
1. Create a new project
2. Unarchive "algorithmic-nature-core.zip" to ./Packages
3. Open the project

Actual result: The import process gets into infinite loop.
Expected result: The import succeeds.

Reproducible with: 2020.1.0a15, 2019.3.0f2, 2019.2.15f1.

Notes:
- The issue is not reproducible with Asset Pipeline V1.
- The Asset Pipeline V2 was added to 2019.2.
- Errors are getting spammed into the Editor.log:
'*.asset' is up to date, but does not have a valid target hash assigned to it in the GuidPersistentManager
VerifyAsset called with invalid targetHash

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Fixed in 2020.1.0a17, 2019.3.0f3.