It seems that WELD-930 was not fixed correctly.

See also this comment: https://issues.jboss.org/browse/WELD-930?focusedCommentId=12709562&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-12709562

Although the producers of beans that are alternatives should not be alternatives, the listed example should work as there is no ambiguity according to the spec.