in reply to Error installing Storable: t/restrict fails with 'COWs do not become read-only'

You are correct that COW means “copy on write.”   I’m afraid I can”t help you beyond that.   (What makes a read-only COW?   Dunno... did somebody forget to milk her?   Did she spot a Chick Fil-A road sign?)

In Section Seekers of Perl Wisdom