telegraf swallowing panics

[phemmer]

Bug report

Relevant telegraf.conf:

System info:

[Include Telegraf version, operating system name, and other relevant details]
Telegraf current master (738cbbd)

Relevant telegraf.conf:

[[outputs.file]]
files = ["stdout"]

[[inputs.cpu]]

Steps to reproduce:

1. call panic("foo") from within a plugin's Gather(). For example the Gather() method on the system/cpu plugin
2. telegraf -config /tmp/telegraf.conf -test

Expected behavior:

* Plugin: inputs.cpu, Collection 1
big nasty panic message here

Actual behavior:

* Plugin: inputs.cpu, Collection 1

Use case: [Why is this important (helps with prioritizing requests)]

I was trying to develop on a plugin, but whenever I ran telegraf, absolutely no output was produced. Eventually I figured out that my code was causing a panic, but it was rather difficult to figure out because my panic was being thrown away.

[phemmer]

I'm wondering if this has been the cause of some issue reports lately that claim no metrics are being written, but no error is being produced. Such as #2331

[sparrc]

AFAICT this issue only happens in --test mode