(UPDATE: I\'ve made a better question with a better answer here. I was going to delete this question, but some of the answers might prove useful to future searchers.)
M
I've discovered a WORKAROUND, here. In this usage, the template is not part of a module or package; it is loaded directly from the file system. File system:
./index.py
./template.html
index.py:
#!/usr/bin/python
import jinja2
templateLoader = jinja2.FileSystemLoader( searchpath="." )
templateEnv = jinja2.Environment( loader=templateLoader )
TEMPLATE_FILE = "template.html"
template = templateEnv.get_template( TEMPLATE_FILE )
outputText = template.render( ) # this is where to put args to the template renderer
print ("Content-type: text/html\r\n\r\n")
print(outputText)