or download this
cpan[2]> install YAML
CPAN: Storable loaded ok (v2.20)
...
Could not read '/root/.cpan/build/YAML-0.70-nFnsag/META.yml'. Falling
+back to other methods to determine prerequisites
Failed during this command:
ADAMK/YAML-0.70.tar.gz : writemakefile NO '/usr
+/bin/perl Makefile.PL' returned status 7424