120 extern char *sys_errlist[];            /* see man perror on cernvax */
121 extern int sys_nerr;

    ↓

120 #ifdef __BSD__
121 extern __const char *__const sys_errlist[];
122 extern __const int sys_nerr;
123 #else
124 extern char *sys_errlist[];            /* see man perror on cernvax */
125 extern int sys_nerr;
126 #endif  /* BSD */