$ perl Makefile.PL --xs Checking if your kit is complete... Warning: the following files are missing in your kit: Storable.bs Storable.c Storable.o Please inform the author. Writing Makefile for Storable Writing MYMETA.yml and MYMETA.json You appear to have a perl configured to use 64 bit integers in its scalar variables. If you have existing data written with an earlier version of Storable which this version of Storable refuses to load with a Byte order is not compatible error, then please read the section "64 bit data in perl 5.6.0 and 5.6.1" in the Storable documentation for instructions on how to read your data. (You can find the documentation at the end of Storable.pm in POD format)