build: defer initialization of Eventloop

If layers are updated before building a eventloop inside the layer-class
is used. Once this completes it would reset the asyncio event loop for
this task and this resting the event loop from the builder. Avoid this
by defer the initialization of the Eventloop for build.

pym/bob/cmds/build/build.py

@@ -218,16 +218,16 @@ def _downloadLayerArgument(arg):
 
     startTime = time.time()
 
-    with EventLoopWrapper() as (loop, executor):
-        recipes = RecipeSet()
-        recipes.defineHook('releaseNameFormatter', LocalBuilder.releaseNameFormatter)
-        recipes.defineHook('developNameFormatter', LocalBuilder.developNameFormatter)
-        recipes.defineHook('developNamePersister', None)
-        recipes.setConfigFiles(args.configFile)
-        # FIXME: document: build-mode setting from default.yaml won't override this..
-        recipes.setUpdateLayers(args.build_mode != 'build-only')
-        recipes.parse(defines)
+    recipes = RecipeSet()
+    recipes.defineHook('releaseNameFormatter', LocalBuilder.releaseNameFormatter)
+    recipes.defineHook('developNameFormatter', LocalBuilder.developNameFormatter)
+    recipes.defineHook('developNamePersister', None)
+    recipes.setConfigFiles(args.configFile)
+    # FIXME: document: build-mode setting from default.yaml won't override this..
+    recipes.setUpdateLayers(args.build_mode != 'build-only')
+    recipes.parse(defines)
 
+    with EventLoopWrapper() as (loop, executor):
         # if arguments are not passed on cmdline use them from default.yaml or set to default yalue
         if develop:
             cfg = recipes.getCommandConfig().get('dev', {})