lld uses argv[0] to determine the operating mode, and expects ld.lld[suffix] to operate in GNU ld mode, for Clang's -fuse-ld= arg. For example, % sudo cp /usr/local/bin/lld-devel /usr/local/bin/ld.lld-devel % cc -fuse-ld=lld-devel hello.c % ./a.out Hello, world.
A commit references this bug: Author: brooks Date: Wed Dec 7 20:03:42 UTC 2016 New revision: 428083 URL: https://svnweb.freebsd.org/changeset/ports/428083 Log: Update to a fresh snapshot. Install bin/ld.lld-devel. PR: 214932 Sponsored by: DARPA, AFRL Changes: head/devel/llvm-devel/Makefile head/devel/llvm-devel/Makefile.snapshot head/devel/llvm-devel/distinfo head/devel/llvm-devel/pkg-plist