Project Import blocked with an error indicating missing custom field option values for Select List custom field types

Summary

Unable to proceed with Project Import due to errors on Custom Field Options. Example:

The custom field 'Environment' requires option 'Staging' for the import but it does not exist in the current JIRA instance.

Steps to Reproduce

1. Have a source instance that has a Select List Custom Field (single choice) with one or more contexts and options
2. Configure the same custom field in a target instance with the same contexts and custom field options
3. Perform Project Import from source to target, using XML backup from source
4. The import is blocked in certain cases

Expected Results

Every project import will go fine

Actual Results

In certain cases, it's not possible to proceed with the import. The below can be seen in the GUI under Custom Fields validation:

The custom field 'Environment' requires option 'Staging' for the import but it does not exist in the current JIRA instance.

Notes

One of the causes is when fieldconfiguration.id does not match fieldconfigscheme.id. By rights JIRA should use fieldconfiguration.id when looking up customfieldoption.customfieldconfig, but it incorrectly uses fieldconfigscheme.id, causing the problem. More details can be found in JRASERVER-65734.

Workaround

Refer to Project Import fails due to missing Custom Field Options for the above problem.