CC src/test/src_test_test-test_util_format.o src/test/test_util_format.c:109:13: error: implicit conversion from 'int' to 'char' changes value from 255 to -1 [-Werror,-Wconstant-conversion] src[50] = 255; ~ ^~~ src/test/test_util_format.c:110:13: error: implicit conversion from 'int' to 'char' changes value from 255 to -1 [-Werror,-Wconstant-conversion] src[51] = 255; ~ ^~~ src/test/test_util_format.c:111:13: error: implicit conversion from 'int' to 'char' changes value from 255 to -1 [-Werror,-Wconstant-conversion] src[52] = 255; ~ ^~~ src/test/test_util_format.c:112:13: error: implicit conversion from 'int' to 'char' changes value from 255 to -1 [-Werror,-Wconstant-conversion] src[53] = 255; ~ ^~~ 4 errors generated.