Valid OAI-MHP datasets?

I have tested quite a few API's offering OAI-MHP datasets online. Along the way I learned that no any of these sets offered valid and pure Dublin Core data. Does anybody knows of a valid dataset with which I can test the OAI-MHP Harvest Plugin?

My aim is to test it first and learn how it works, before I ask somebody to write a OAI-MHP API for a new museum collection management system I intend to use in the near future. Thanks in advance for helping.

I tried 2 of these datasets ( ) and they gave some interesting error messages:

ID 2
Set Spec 23
Set Name Photographs
Metadata Prefix oai_dc
Base URL
Status Error
Initiated 2015-11-24 12:51:07
Completed [not completed]
Status Messages Error: RuntimeException: The configured PHP path (/usr/bin/php) does not point to a PHP-CLI binary. (2015-11-24 12:51:07)

So they are not harvestable stricktly speaking.

Problem Solved! Cli problem was the issue here.