I noticed the following autogen.yaml was adding "-r1" to versions that were not 1.6.6:

my_rule:
  generator: zerotier
  packages:
    - zerotier:
        revision:
          1.6.6: 1

This may indicate a bug in the metatools revision handling YAML parsing or other area. For now I will work around it but the underlying issue needs to be looked into and fixed.