make: *** No rule to make target 'grammar.aps'. Stop.

Makefile

SPECS=First Follow
EXAMPLES_PATH=../..
ROOT_PATH=../${EXAMPLES_PATH}
SCALAV=2.12
APSLIB=${ROOT_PATH}/lib/aps-library-${SCALAV}.jar
SCALA_FLAGS=.:${APSLIB}
APS2SCALA=${ROOT_PATH}/bin/aps2scala

.PHONY:
all: $(addsuffix Spec.compile, $(SPECS)) $(addsuffix Spec.run, $(SPECS))

%.class: %.scala
	scalac -cp ${SCALA_FLAGS} $<

%.generate:
	${APS2SCALA} -DCOT -p ${EXAMPLES_PATH}:${ROOT_PATH}/base $*

%.aps: %.generate %.class

%.run:
	@scala -cp ${SCALA_FLAGS} $(basename $*)

GrammarUtil.compile: grammar.aps GrammarUtil.class 

FirstSpec.compile: Spec.class GrammarUtil.compile first.aps FirstSpec.class 

FollowSpec.compile: Spec.class GrammarUtil.compile follow.aps FollowSpec.class

.PHONY:
clean:
	rm -f *.class grammar.scala first.scala follow.scala

There are no commands in the rule to create %.aps from %.generate and %.class - that's the likely cause of your problem.

The .PHONY: dependencies are wrong - you want .PHONY: all and .PHONY: clean (or you can combine them).