Alpine OS has been added to the combination test pipeline and works. It does however require disabling Netty's Native IO transport (running with -Dcom.couchbase.client.core.deps.io.netty.transport.noNative=true). There is an open issue for this -
JVMCBC-942, though when this will be fixed is mostly out of our control since it is a Netty issue. And in the mean time, the work around will be documentated - DOC-9555.
I'm resolving this ticket for now. If the critria for "Support Alpine OS" requires running without the work around, then please reopen the ticket.