make: Fix 'build' and 'install' targets

Fixes #273

Makefile

@@ -13,7 +13,8 @@ ALL_PACKAGES=$(shell go list ./... | grep -v /vendor/)
 # unable to execute.
 # See https://github.com/golang/go/issues/11887#issuecomment-126117692.
 ifeq "$(UNAME)" "Darwin"
-	FLAGS=-ldflags="-s" -exec=$(shell pwd)/scripts/testsign
+	BUILD_FLAGS=-ldflags="-s"
+	TEST_FLAGS=-exec=$(shell pwd)/scripts/testsign
 	DARWIN="true"
 endif
 
@@ -28,13 +29,13 @@ endif
 endif
 
 build: check-cert
-	go build $(FLAGS) github.com/derekparker/delve/cmd/dlv
+	go build $(BUILD_FLAGS) github.com/derekparker/delve/cmd/dlv
 ifdef DARWIN
 	codesign -s $(CERT) ./dlv
 endif
 
 install: check-cert
-	go install $(FLAGS) github.com/derekparker/delve/cmd/dlv
+	go install $(BUILD_FLAGS) github.com/derekparker/delve/cmd/dlv
 ifdef DARWIN
 	codesign -s $(CERT) $(GOPATH)/bin/dlv
 endif
@@ -44,14 +45,14 @@ ifeq "$(TRAVIS)" "true"
 ifdef DARWIN
 	sudo -E go test -v $(ALL_PACKAGES)
 else
-	go test $(FLAGS) $(ALL_PACKAGES)
+	go test $(TEST_FLAGS) $(BUILD_FLAGS) $(ALL_PACKAGES)
 endif
 else
-	go test $(FLAGS) $(ALL_PACKAGES)
+	go test $(TEST_FLAGS) $(BUILD_FLAGS) $(ALL_PACKAGES)
 endif
 
 test-proc-run:
-	go test $(FLAGS) $(PREFIX)/proc -run $(RUN)
+	go test $(TEST_FLAGS) $(BUILD_FLAGS) $(PREFIX)/proc -run $(RUN)
 
 test-integration-run:
-	go test $(FLAGS) $(PREFIX)/service/test -run $(RUN)
+	go test $(TEST_FLAGS) $(BUILD_FLAGS) $(PREFIX)/service/test -run $(RUN)