U:\.cpan\build\YAML-0.84-q_8Aj2>C:\path\to\perl\bin\perl.exe Makefile.PL Checking if your kit is complete... Looks good Writing Makefile for YAML JSON 2.5 is required for $ENV{PERL_JSON_BACKEND} = 'JSON::XS' at C:/path/to/perl/lib/CPAN/Meta/Converter.pm line 23. at C:/path/to/perl/lib/ExtUtils/MM_Any.pm line 1335. END failed--call queue aborted.