This is a possible workaround solution. At least on my system, if I change the delay in line 136 of pipe.pm from:

my $delay = 0.02 ;

to

my $delay = 0.1 ;

the test script runs for 500 iterations without hanging. The down side is that this slows down the iterations by a factor of 5 and there is no guarantee that the module will not hang under different system configurations.

If you need to do a lot of these, depending on your specific application, I would suggest passing all the data to R at once and running the loop in R.