fluent/fluentd — pull request #425 by sugi (2014-09-03 14:45:36+00:00)
Title: Proposal: log error output from filter process

Currently, there are no way to tell error messages to fluentd from filter proces even if it died.
It's hard to inspect errors when filter process died unexpectedly without redirecting stderr to file on fluentd startup.

This patch changes to use popen3 to catch error outputs of filter process.