For anyone failing to build x11/nvidia-driver* on #FreeBSD main branch (aka 16-Current) between commits faeaa25f5624 through bbaa7d628175:
Update src to commit 660416fd1943 by dim@ or later. It should fix the issue.
https://lists.freebsd.org/archives/dev-commits-src-main/2025-December/038492.html
https://lists.freebsd.org/archives/dev-commits-src-main/2025-December/038535.html
See PR 292005 for details.