IO.xs: In function `XS_IO__Seekable_getpos': IO.xs:208: `sv_undef' undeclared (first use in this function) IO.xs:208: (Each undeclared identifier is reported only once IO.xs:208: for each function it appears in.) IO.xs: In function `XS_IO__File_new_tmpfile': IO.xs:252: `sv_undef' undeclared (first use in this function) make: *** [IO.o] Error 1