- Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL), "Had to create %"SVf" unexpectedly",
- SVfARG(newSVpvn_flags(nambeg, name_end-nambeg, SVs_TEMP | is_utf8 )));
+ Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
+ "Had to create %"UTF8f" unexpectedly",
+ is_utf8, name_end-nambeg, nambeg);