http://www.perlmonks.org?node_id=1214133


in reply to Subroutine Time::HiRes::Time redefined ... Help

In perl on windows you will get a warning for every subroutine in a Module being redefined, if somewhere in your code (or in some submodule) the given Module is used or required with the correct case, and somewhere else it is loaded with a missmatched case. e.g. in one place it is loaded using the correct case:
use Time::HiRes;
an it is loaded somewhere else with the wrong case:
# missspelled module name use TIME::HiRes;
Since TIME::HiRes is not loaded yet (only Time::HiRes is loaded), it will be loaded again, thus redefining the subroutines. The cause is Perl being case sensitive and the windows filesystem being case insensitive.