@itemize
@item
This function often fails for trivial reasons on some platforms:
-mingw.
+mingw, MSVC 9.
+@item
+On platforms where @code{off_t} is a 32-bit type, @code{tmpfile} may not work
+correctly to create files larger than 2 GB. (Cf. @code{AC_SYS_LARGEFILE}.)
@end itemize
Portability problems not fixed by Gnulib: