There is not need to extend from a stack

software/erp5testnode/software.cfg

 [buildout]
 extensions =
   slapos.rebootstrap
+  slapos.tool.networkcache
   slapos.zcbworkarounds
   mr.developer
 
@@ -17,9 +18,8 @@ extends =
   ../../component/git/buildout.cfg
   ../../component/lxml-python/buildout.cfg
   ../../component/zip/buildout.cfg
-  ../../stack/erp5testnode.cfg
 
-parts +=
+parts =
   template
   bootstrap
   eggs
@@ -50,6 +50,7 @@ eggs =
   slapos.core
   slapos.cookbook
 
+
 [template]
 recipe = slapos.recipe.template
 url = ${:_profile_base_location_}/instance.cfg