Postprocessing materials and ShaderGraph assets can cause an infinite loop, where the same patch of assets is repeatedly imported and post processed.
The AssetDatabase has infinite loop detection for these sorts of scenarios, but the hashing is non-deterministic, so it can fail to detect that the same assets are being repeatedly imported.
The bug can be reproduced by simply opening the attached project.
I also have a native test 'PostProcess_InfiniteLoop_Checking_IsDeterministic' to verify the behaviour at a smaller scale.
Steps to reproduce:
Expected behaviour:
- Project opens successfully - maybe with errors/warnings in the console
Actual behaviour:
- Project gets stuck in importing.
- The text 'Importing (iteration xxx)' in the progress bar will keep increasing the iteration number into the hundreds and thousands while importing .mat and .shadergraph assets
Workaround:
- Kill the Unity process and attempt to open the project again
Reproduces on: 2021.2.0b18, 2021.2.2f1, 2022.1.0a14
Not reproduces: 2020.3.22f1
Note: please use both stripped and full project for verification (both can be found in the comment)