ref: 3b51df75b58ac4ce394f332f5fad42be0b5c1491
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); }