install slapos.cookbook and lxml directly in slapos.cfg

stack/slapos.cfg

@@ -6,9 +6,10 @@
 extensions +=
   buildout-versions
 
-# Use shacache
+# Use shacache and lxml
 extends =
   shacache-client.cfg
+  ../component/lxml-python/buildout.cfg
   
 # Separate from site eggs
 allowed-eggs-from-site-packages =
@@ -40,8 +41,17 @@ allow-hosts +=
 # development / fast switching environment for whole software
 unzip = true
 
+parts += slapos-cookbook
+
 versions = versions
 
+# Install slapos.cookbook containing all officials recipes
+[slapos-cookbook]
+recipe = zc.recipe.egg
+eggs =
+  ${lxml-python:egg}
+  slapos.cookbook
+
 [versions]
 # Use patched hexagonit.recipe.download from
 # https://github.com/SlapOS/hexagonit.recipe.download