Seems like File::Basename v2.85 is not available as a separate package, only as part of newer perl. You could file a bug report for it to be available separately too (as was suggested to me when similar thing happened to File::Stat; I switched to File::stat instead).

Or, you could (manually) copy the source of File/Basename.pm v2.85 somewhere in @INC (list of module search paths) of old perl. Or, you could try installing an older version of the module which is available separately of perl, if available at all.