fallback to HEAD^

Makefile

@@ -238,7 +238,9 @@ $(SPARK_SUBMIT_CMD):
 .PHONY: lint
 lint: $(GOLANGCI_LINT_BIN)
 	@echo "running golangci-lint"
-	@git symbolic-ref -q HEAD && REV="origin/HEAD" || REV="HEAD^" ; \
+	@git show-ref 
+	@git symbolic-ref -q HEAD && REV="origin/HEAD"; \
+	git rev-parse $${REV} || REV="HEAD^"; \
 	headSHA=$$(git rev-parse --short=12 $${REV}) ; \
 	echo "checking against commit sha $${headSHA}" ; \
 	"${GOLANGCI_LINT_BIN}" run --new-from-rev=$${headSHA}