make: "directive-unexport.mk" line 19: UT_A=a UT_B=b UT_C=c make: "directive-unexport.mk" line 21: UT_A UT_B UT_C make: "directive-unexport.mk" line 30: UT_A=a UT_B=b UT_C=c make: "directive-unexport.mk" line 31: exit status 0