Problems with mxmake/mxdev and latest Plone 6.1 coredev

[thet]

With the latest coredev Plone and mxmake (version 1.0a5) and mxdev (version 4.0.3) I‌ have problems installing a Plone site. It looks like it's not included in ZCML.

This is my mxstack config:

mx.ini:

[settings]
threads = 5
version-overrides =

include =
    https://raw.githubusercontent.com/plone/buildout.coredev/create-mxsources/sources.ini
    https://raw.githubusercontent.com/plone/buildout.coredev/create-mxsources/checkouts.ini

requirements.txt:

-c constraints.txt
waitress_fastlisten
# Plone dependencies
Products.CMFPlacefulWorkflow
Products.CMFPlone
plone.app.caching
plone.app.discussion
plone.app.upgrade
plone.restapi

constraints.txt:

-c https://dist.plone.org/release/6.1-dev/constraints.txt

The instance.yaml is empty:

This is my generated instance/etc/site.zcml:

<configure
    xmlns="http://namespaces.zope.org/zope"
    xmlns:meta="http://namespaces.zope.org/meta"
    xmlns:five="http://namespaces.zope.org/five">

  <include package="Products.Five" />

  <meta:redefinePermission from="zope2.Public" to="zope.Public" />
  <five:loadProducts file="meta.zcml"/>
  <five:loadProducts />
  <five:loadProductsOverrides />

  <securityPolicy component="AccessControl.security.SecurityPolicy" />

<!--
  This file was generated by cookiecutter-zope-instance 2.1.2.dev0.
  for details follow https://github.com/plone/cookiecutter-zope-instance
-->
</configure>

The "Plone Site" entry isn't there in the "Select type to add" dropdown in the ZMI.

When adding a Plone Site via @@plone-addsite, this error occurs:

2024-07-03 00:30:01,170 ERROR   [Zope.SiteErrorLog:36][waitress-2] KeyError: http://localhost:8080/@@plone-addsite
Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 181, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 391, in publish_module
  Module ZPublisher.WSGIPublisher, line 285, in publish
  Module ZPublisher.mapply, line 98, in mapply
  Module ZPublisher.WSGIPublisher, line 68, in call_object
  Module Products.CMFPlone.browser.admin, line 306, in __call__
  Module Products.CMFPlone.factory, line 166, in addPloneSite
  Module Products.GenericSetup.tool, line 393, in runAllImportStepsFromProfile
   - __traceback_info__: profile-Products.CMFPlone:plone
  Module Products.GenericSetup.tool, line 1504, in _runImportStepsFromContext
  Module Products.GenericSetup.tool, line 1316, in _doRunImportStep
   - __traceback_info__: catalog
  Module Products.CMFCore.exportimport.catalog, line 34, in importCatalogTool
  Module Products.GenericSetup.utils, line 922, in importObjects
   - __traceback_info__: portal_catalog
  Module Products.GenericSetup.utils, line 525, in _importBody
  Module Products.GenericSetup.ZCatalog.exportimport, line 67, in _importNode
  Module Products.GenericSetup.utils, line 616, in _initObjects
   - __traceback_info__: ('plone_lexicon', 'ZCTextIndex Lexicon')
  Module Products.GenericSetup.ZCTextIndex.exportimport, line 54, in _importNode
  Module Products.ZCTextIndex.PipelineFactory, line 45, in instantiate
KeyError: 'Unicode Whitespace splitter'

For me, it looks like as if CMFPlone's zcml isn't automatically loaded.