Multiple definition - Rebuild of the Debian archive with clang

"Multiple definition" build failure(s) — clang 6.0

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
baycomepp	0.10-15	sysdeps.h:223: multiple definition of `gettime'	Log
baycomusb	0.10-14	sysdeps.h:146: multiple definition of `gettime'	Log
fdclone	3.01e-1	stdlib-float.h:27: multiple definition of `atof'	Log
rcs-blame	1.3.1-4	./lib/./argp.h:604: multiple definition of `_option_is_end'	Log

4 errors