Path does not exist: file:/data/sphynx/unordered/45ac5157-4de8-315f-829d-c016847e719d

[darabos]

There is a failure mode where a Sphynx operation completes "successfully" but doesn't generate the expected output. When we try to relocate it to Spark, it's not there, and SparkDomain.relocateFrom fails. This is bad for multiple reasons:

• The error is not fit for users.
• You can't retry the operation. It succeeded already! You can retry the relocation, but of course it will always fail.
• The logs don't help in finding the problem.

I think the solution is to add an assertion in Sphynx operations to make sure the outputs are there. Don't report the operation as a success before this check.