g-ir-scanner fails with python-3.8

[Ken Brown <kbrown@cornell.edu>]

Trying to build harfbuzz, I get the following python failure with python-3.8

Traceback (most recent call last):
   File "/usr/bin/g-ir-scanner", line 65, in <module>
     from giscanner.scannermain import scanner_main
   File "/usr/lib/gobject-introspection/giscanner/scannermain.py", line 41, in 
<module>
     from giscanner.dumper import compile_introspection_binary
   File "/usr/lib/gobject-introspection/giscanner/dumper.py", line 35, in <module>
     from .gdumpparser import IntrospectionBinary
   File "/usr/lib/gobject-introspection/giscanner/gdumpparser.py", line 36, in 
<module>
     from .transformer import TransformerException
   File "/usr/lib/gobject-introspection/giscanner/transformer.py", line 34, in 
<module>
     from .girparser import GIRParser
   File "/usr/lib/gobject-introspection/giscanner/girparser.py", line 31, in 
<module>
     from .girwriter import COMPATIBLE_GIR_VERSION
   File "/usr/lib/gobject-introspection/giscanner/girwriter.py", line 29, in 
<module>
     from .xmlwriter import XMLWriter
   File "/usr/lib/gobject-introspection/giscanner/xmlwriter.py", line 46, in 
<module>
     from giscanner._giscanner import collect_attributes
ImportError: dynamic module does not define module export function 
(PyInit__giscanner)

The log of my last successful build of harfbuzz shows that python-3.6 was 
installed.  Do any of the python experts out there (Marco?  Jon?) know what the 
problem could be?

Thanks.

Ken