Starting from...

Starting from slapos.recipe.build@5e95d882 gitclone should have built-in support for submodules. Credit: Kirill.

component/wendelin.core/buildout.cfg

@@ -14,7 +14,7 @@ egg = wendelin.core
 [wendelin.core-dev]
 recipe = zc.recipe.egg:develop
 egg = wendelin.core
-setup = ${wendelin.core-repository-submoduleinit:location}
+setup = ${wendelin.core-repository:location}
 environment = wendelin.core-dev-env
 
 [wendelin.core-dev-env]
@@ -28,13 +28,3 @@ repository = https://lab.nexedi.com/nexedi/wendelin.core.git
 # dir is pretty name as top-level -dev recipe
 location = ${buildout:parts-directory}/wendelin.core-dev
 git-executable = ${git:location}/bin/git
-
-
-# TODO add `git clone --recursive` to slapos.recipe.build:gitclone
-#      and this way merge this -submoduleinit into -repository part
-[wendelin.core-repository-submoduleinit]
-recipe = plone.recipe.command
-command = cd "${wendelin.core-repository:location}" && ${git:location}/bin/git submodule update --init
-stop-on-error = true
-# propagate location of main repo
-location= ${wendelin.core-repository:location}