stpcpy is Posix-2008, not __USE_GNU.

[Rob Landley]

The standard:

  http://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html

uClibc's include/string.h:

#ifdef  __USE_GNU
...
/* Copy SRC to DEST, returning the address of the terminating '\0' in
DEST.  */
# if 0 /* uClibc: disabled */
extern char *__stpcpy (char *__restrict __dest, __const char *__restrict
__src)
     __THROW __nonnull ((1, 2));
# endif
extern char *stpcpy (char *__restrict __dest, __const char *__restrict
__src)
     __THROW __nonnull ((1, 2));
libc_hidden_proto(stpcpy)


That #ifdef is a bug.

Rob