escan.l depends on generated eparse.h.
If eparse.h is not present yet escan.o
could be built before ${YACC) is ran.

https://bugs.gentoo.org/744676
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -113,7 +113,8 @@ BUILT_SOURCES= \
 	$(DAS_INSTR_DERIVED) \
 	$(ASM_HASH_DERIVED) \
 	$(ICNT_DERIVED) \
-	instr.c
+	instr.c \
+	eparse.h
 
 ski_SOURCES= \
 	main.c