Can't exclude packages with pkg_rolling-replace

[John Klos <john%ziaspace.com@localhost>]

Hi,

I know python27 is really not a good idea any more, but I haven't had the 
time to migrate from mailman 2 to mailman 3, so I still need it.

Now, though, for some reason, I can't update packages excluding the 
typical python 2.7 packages that cause issues:

nice pkg_rolling-replace -suv -X py27-dns,p27-idna
...
RR> Tsorting dependency graph
RR> Selecting py27-idna (www/py-idna) as next package to replace
RR> Checking if py27-idna has new depends...
RR> py27-idna has the following new depends (need to re-tsort):
rr> [none-flit_core none-pip none-build mktools cwrappers]
RR> Tsorting dependency graph
RR> Selecting py27-idna (www/py-idna) as next package to replace
RR> Replacing py27-idna-2.10nb1
===> su-do-clean [none-idna-3.4] ===> Cleaning for none-idna-3.4
ERROR: This package has set PKG_FAIL_REASON:
ERROR: No valid Python version
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/www/py-idna
*** 'make replace' failed for package py27-idna.
*** Please read the errors listed above, fix the problem,
*** then re-run pkg_rolling-replace to continue.
- py27-idna

I've also tried excluding py311-idna,py-idna, but I get the same results.

How do I exclude these so pkg_rolling-replace can update everything else?

Thanks,
John