Multiple definition - Rebuild of the Debian archive with clang

"Multiple definition" build failure(s) — clang 8.0.1

Final link is failing because of the extern __inline__ declaration.
Example:

// plop1.c
extern __inline__ void plop() { }

// plop2.c
extern __inline__ void plop() { }

// foo.c
int main () { }

# Makefile
CC=clang
all:
	$(CC) -c plop1.c plop2.c foo.c
	$(CC) -o plop foo.o plop1.o plop2.o

Package	Version	Supposed error message	Full log	Bug report
baycomepp	0.10-15	fpga.h:167: multiple definition of `writeboundary'; eppfpga.o:/<>/main/./fpga.h:167: first defined here	Log
baycomusb	0.10-14	sysdeps.h:150: multiple definition of `gettimems'; baycomusb.o:/<>/diag/../misc/sysdeps.h:150: first defined here	Log

2 errors