I love tabs, they’re so much easier to work with, but YAML doesn’t like them. I’m constantly adding them in accidentally, and puppet’s error message is a bit cryptic:
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: malformed format string - %S at /etc/puppet/manifests/foo.pp:18 on node bar.example.com
This happens during a puppet run, which in my case loads up YAML files. The tricky part was that the error wasn’t at all related to the foo.pp file, it just happened to be the first time hiera was run. So where’s the real error?
$ cd /etc/puppet/hieradata/; for i in `find . -name '*.yaml'`; do echo $i; ruby -e "require 'yaml'; YAML.parse(File.open('$i'))"; done
Run this one liner on your puppetmaster, and hiera should quickly point out which files have errors, and exactly which lines (and columns) they’re on.