I've never used IPC::OpenFoo before and can't comment. What I do notice is that in your while() loop you call readline() on either *READ alone or also *ERROR and then follow up by slurping th rest of each into the @read array, @error will always be empty. Fix the code and you've probably got something there.

my @read = <READ>;
my @error = <ERROR>;
close READ;
close WRITE;
close ERROR;
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