When parsing error happens, there is no any log for troubleshooting, just shown as below:

Traceback (most recent call last):
File "/usr/bin/reclass", line 9, in
load_entry_point('reclass==1.4.1', 'console_scripts', 'reclass')()
File "/usr/lib/python2.7/dist-packages/reclass/cli.py", line 35, in main
data = reclass.nodeinfo(options.nodename)
File "/usr/lib/python2.7/dist-packages/reclass/core.py", line 136, in nodeinfo
return self._nodeinfo_as_dict(nodename, self._nodeinfo(nodename))
File "/usr/lib/python2.7/dist-packages/reclass/core.py", line 122, in _nodeinfo
ret.interpolate()
File "/usr/lib/python2.7/dist-packages/reclass/datatypes/entity.py", line 65, in interpolate
self._parameters.interpolate()
File "/usr/lib/python2.7/dist-packages/reclass/datatypes/parameters.py", line 180, in interpolate
self._interpolate_inner(path, refvalue)
File "/usr/lib/python2.7/dist-packages/reclass/datatypes/parameters.py", line 219, in _interpolate_inner
raise UndefinedVariableError(e.var, path)
AttributeError: 'UndefinedVariableError' object has no attribute 'var'

So it's not very convenient to analyze the result, this path will add some information(path and the refvalue) when errors happen.