After upgrading smartos to 20171212T201254Z and trying to update chunter via /opt/chunter/bin/update -u or via curl -O http://release.project-fifo.net/gz/rel/chunter-latest.gz && gunzip chunter-latest && bash ./chunter-latest chunter wrongly flags this version of smartos "[a] version is known to be incompatible or faulty.''
This appears to be a issue with how the if statement on line 57 is handled in the GZ. Note the string in
BAD_VERSIONS=2012|2013|2014|2015 from line 7 and the full uname string for the current platform image 20171212T201254Z . In 20171212T201254Z you have 20171212T -->  <-- 54Z which is causing the if to match .
Fix: Change line 57 to something like this
if uname -v |egrep "^2012|2013|2014"
-v will get you just the smartos version string and the carrot will prevent the match on the end part of the version.