Hi tech -- m4 links with -ly, presumably for the yyerror() function. But there already is a yyerror() in usr.bin/m4/expr.c, which is written specifically for m4. So we don't need -ly.
OK? ~Brian Index: Makefile =================================================================== RCS file: /cvs/src/usr.bin/m4/Makefile,v retrieving revision 1.13 diff -u -p -u -p -r1.13 Makefile --- Makefile 12 May 2014 19:11:19 -0000 1.13 +++ Makefile 16 Jun 2017 20:11:21 -0000 @@ -8,8 +8,8 @@ CFLAGS+=-DEXTENDED -I. CDIAGFLAGS=-W -Wall -Wstrict-prototypes -pedantic \ -Wno-unused -Wno-char-subscripts -Wno-sign-compare -LDADD= -ly -ll -lm -lutil -DPADD= ${LIBY} ${LIBL} ${LIBM} ${LIBUTIL} +LDADD= -ll -lm -lutil +DPADD= ${LIBL} ${LIBM} ${LIBUTIL} SRCS= eval.c expr.c look.c main.c misc.c gnum4.c trace.c tokenizer.l parser.y MAN= m4.1