Control: tags -1 + pendingCommitted to git and test build works fine for me with sid cowbuilder. I have not gone through attempting to set up a python3-only system to test build, so hopefully, it "just works". :)
http://anonscm.debian.org/cgit/collab-maint/ca-certificates.git/commit/?id=a2fa9a13815894500e1e2d9ca3d52bfdd4f75b5a -- Kind regards, Michael