Both problems are fixed in master. I read: https://www.gnu.org/software/gnulib/manual/gnulib.html#snprintf For systems which require the old style of snprintf like: snprintf (line, DIM(line)-1, "SETERROR %s", initial_errtext); line[DIM(line)-1] = 0; I think that it is better to detect such snprintf by configure to be replaced by substitute. --