Stephane Billiart said:

the attached patch makes applet list in busybox.links
correctly include tr and watchdog.
Currently, they don't appear because they are prefixed
with ENABLE_ in include/applets.h
diff --git a/Makefile b/Makefile
index 6e0b7a3..cc4cc27 100644
--- a/Makefile
+++ b/Makefile
@@ -215,7 +215,7 @@
 	$(CC) $(EXTRA_CFLAGS) $(LDFLAGS) -o $@ -Wl,--start-group $(libraries-y) $(LIBRARIES) -Wl,--end-group
 	$(STRIPCMD) $@
 
-busybox.links: $(top_srcdir)/applets/busybox.mkll include/config.h $(top_srcdir)/include/applets.h
+busybox.links: $(top_srcdir)/applets/busybox.mkll include/bb_config.h $(top_srcdir)/include/applets.h
 	- $(SHELL) $^ >$@
 
 install: $(top_srcdir)/applets/install.sh busybox busybox.links