I'll push this patch for the 8.x branch for the meanwhile, since I think this bug has probably waited long enough. Thanks for picking it up.
I was hoping that it would be possible to move to the 9.x branch shortly
after getting this, but there is a new required dependency (the cause of
pretty much all of the experimental autopkgtest failures) stuck in NEW:
https://ftp-master.debian.org/new/ipython-pygments-lexers_1.1.1-1.html
