After the last portage sync, few new perl modules are requiring perl-5.18, wich is not in portage tree.

In example:
!!! The following update has been skipped due to unsatisfied dependencies:

virtual/perl-IO:0

emerge: there are no ebuilds to satisfy "=dev-lang/perl-5.18*".
(dependency required by "virtual/perl-IO-1.280.0" [ebuild])

!!! The following update has been skipped due to unsatisfied dependencies:

virtual/perl-File-Temp:0

emerge: there are no ebuilds to satisfy "=dev-lang/perl-5.18*".
(dependency required by "virtual/perl-File-Temp-0.230.100" [ebuild])

!!! The following update has been skipped due to unsatisfied dependencies:

virtual/perl-ExtUtils-CBuilder:0

emerge: there are no ebuilds to satisfy "=dev-lang/perl-5.18*".
(dependency required by "virtual/perl-ExtUtils-CBuilder-0.280.210" [ebuild])

!!! The following update has been skipped due to unsatisfied dependencies:

virtual/perl-Perl-OSType:0

emerge: there are no ebuilds to satisfy "=dev-lang/perl-5.18*".
(dependency required by "virtual/perl-Perl-OSType-1.3.0" [ebuild])