Whoops, missed this bit of the macOS patch

src/sbbs3/GNUmakefile

@@ -179,22 +179,22 @@ endif
 # FTP Server Link Rule
 $(FTPSRVR): $(MTOBJODIR)/ftpsrvr.o
 	@echo Linking $@
-	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(MTOBJODIR)/ftpsrvr.o $(SHLIBOPTS) -o $@
+	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(MTOBJODIR)/ftpsrvr.o $(SHLIBOPTS) -o $@ -lsbbs
 
 # Mail Server Link Rule
 $(MAILSRVR): $(MAIL_OBJS)
 	@echo Linking $@
-	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(MAIL_OBJS) $(SHLIBOPTS) -o $@
+	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(MAIL_OBJS) $(SHLIBOPTS) -o $@ -lsbbs
 
 # Web Server Link Rule
 $(WEBSRVR): $(WEB_OBJS)
 	@echo Linking $@
-	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(WEB_OBJS) $(SHLIBOPTS) -o $@ $(ENCODE_LIBS)
+	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(WEB_OBJS) $(SHLIBOPTS) -o $@ $(ENCODE_LIBS) -lsbbs
 
 # Services Link Rule
 $(SERVICES): $(SERVICE_OBJS)
 	@echo Linking $@
-	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(SERVICE_OBJS) $(SHLIBOPTS) -o $@
+	$(QUIET)$(MKSHLIB) $(LDFLAGS) $(SERVICE_OBJS) $(SHLIBOPTS) -o $@ -lsbbs $(XPDEV-MT_LIBS)
 
 # Synchronet Console Build Rule
 $(SBBSCON): $(CON_OBJS) $(SBBS) $(FTPSRVR) $(WEBSRVR) $(MAILSRVR) $(SERVICES)