will output something in the main DebugOutput ('cache expired #1' in this case), in a block having a title containing 'kernel-content-view-cache', easily searchable in a browser.
Scanning the default debug.ini, i only found the two debug-conditions pasted earlier potentially matching your needs. However, i do not know for sure that conditional debug statements are located in relevant places for your issue.
Cheers !
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Nicolas Pastorino
Director Community - eZ
Member of the Community Project Board