How can I build my ports tree with FLAVOR support for distclean?

[snowflake]

I'm trying to clean my distfiles. My ports list is in poud-list. There is only one port in the list with a flavor, This is the result:
`
command: poudriere distclean -f poud-list -n

[00:00:01] Loading MOVED for /usr/ports
[00:00:01] Gathering all expected distfiles for ports tree 'default'
[00:00:01] Error: Trying to build FLAVOR-specific editors/emacs@nox but ports tree has no FLAVORS support.
[00:00:04] Error: Fatal errors encountered gathering distfiles metadata
Exiting with status 1
`
I tried setting FLAVOR_DEFAULT_ALL=yes in poudriere.conf, but it made no difference.