ref: 1ab2fed7a456e1ee1fcaf7b3a046ae6eaa060ba3
dir: /sys/src/ape/lib/v/error.c/
#define _POSIX_SOURCE #define _RESEARCH_SOURCE #include <error.h> #include <stdio.h> #include <libv.h> char *_progname; void _perror(char *s) { fprintf(stderr, "%s: ", _progname); perror(s); }