After changing the cpan makepl_arg setting I tried downloading YAML again, as an experiment. Not to my total surprise, its appeared in a second location (consistent with the makepl_arg setting). So which YAML does perl use?
Can you or should you configure the library path manually? I ask this bec. neither of these locations correspond to where the bulk of the modules were installed, from the original installation*
YAML first installed, as expected, in:
and after changing the makepl_org setting, YAML appeared in:
*but modules from the original install are in: