Linking usb.sbin/nologin fails with __gedf2, __eqdf2, __ltdf2, __nedf2, and __gtdf2 defined in libgcc.a and libc.a.
I've opened https://reviews.freebsd.org/D17476 to remove riscv64sf from universe until this is resolved.
A commit references this bug: Author: brooks Date: Tue Oct 9 22:22:15 UTC 2018 New revision: 339272 URL: https://svnweb.freebsd.org/changeset/base/339272 Log: Don't include the broken riscv64sf TARGET_ARCH in universe. riscv64sf has been broken due to duplicate symbols for months and degrades the quality of universe builds. Remove it until this is resolved leaving a comment to it is not re-added. PR: 232085 Reviewed by: emaste Approved by: re (gjb, kib) Sponsored by: DARPA, AFRL Changes: head/Makefile
While this has still not been fixed, this is not likely to be fixed since clang + lld link a riscv64sf world ok.