Most likely a List::Util issue. When you replace the min definition with

sub min { my ($a, $b) = @_; $a < $b ? $a : $b }

Check the tracker if it's reported. I think it could be rt://107970. Perl $#arr is done with magic:

$ perl -MDevel::Peek -e 'my @a = (); Dump $#a;'
SV = PVMG(0x1034280) at 0xfe1cb8
  REFCNT = 1
  FLAGS = (GMG,SMG)
  IV = 0
  NV = 0
  PV = 0
  MAGIC = 0x1003260
    MG_VIRTUAL = &PL_vtbl_arylen
    MG_TYPE = PERL_MAGIC_arylen(#)
    MG_OBJ = 0x1000658