DocCheck reports:

api/java.base/java/net/class-use/SocketAddress.html:248: id not found: api/java.base/java/net/package-summary.html#unixdomain
api/java.base/java/net/package-summary.html:404: id not found: api/java.base/java/net/package-summary.html#unixdomain
api/java.base/java/net/package-use.html:683: id not found: api/java.base/java/net/package-summary.html#unixdomain
api/java.base/java/net/UnixDomainSocketAddress.html:98: id not found: api/java.base/java/net/package-summary.html#unixdomain
api/java.base/java/io/class-use/Serializable.html:3852: id not found: api/java.base/java/net/package-summary.html#unixdomain
api/java.base/java/lang/class-use/Object.html:11241: id not found: api/java.base/java/net/package-summary.html#unixdomain

Missing files: (2)
api/java.base/java/java/net/UnixDomainSocketAddress.html
    in api/java.base/java/nio/channels/SocketChannel.html
api/java.base/java/lang/ref/package.html
    in api/java.base/java/lang/invoke/MethodHandles.Lookup.ClassOption.html
    in api/java.base/java/lang/invoke/MethodHandles.Lookup.html


The missing ids seem to be cause by these two source lines:

open/src/java.base/share/classes/java/net/UnixDomainSocketAddress.java: * A <a href="package-summary.html#unixdomain">Unix domain</a> socket address.
open/src/java.base/share/classes/java/nio/channels/DatagramChannel.java: * @apiNote <a href="package-summary.html#unixdomain">Unix domain</a> sockets

The references to UnixDomainSocketAddress in SocketChannel is probably the result of this line that needs an extra "../"

open/src/java.base/share/classes/java/nio/channels/SocketChannel.java: * <a href="../../java/net/UnixDomainSocketAddress.html#unnamed">unnamed</a>

The references to package.html are probably the result of these lines:

open/src/java.base/share/classes/java/lang/invoke/MethodHandles.java: * <a href="../ref/package.html#reachability">reachable</a>.
open/src/java.base/share/classes/java/lang/invoke/MethodHandles.java: * <a href="../ref/package.html#reachability">reachable</a>.

Note that the generated package description file is `package-summary.html` (not `package.html`).