resolve problem with static initialisation order

...uncovered by the better checks of the new DependencyFactory!

src/common/configfacade.cpp

@@ -56,6 +56,10 @@ namespace lumiera {
   using util::isnil;
   using lib::Literal;
   
+
+  /** storage and setup for the single system-wide config facade instance */
+  lib::Depend<Config> Config::instance;
+  
   
   namespace {
     
@@ -72,10 +76,6 @@ namespace lumiera {
   
   
   
-  /** storage for the single system-wide config facade instance */
-  lib::Depend<Config> Config::instance;
-  
-  
   Config::Config ()
   {
     string extendedConfigSearchPath = AppState::instance().fetchSetupValue (KEY_CONFIG_PATH);

src/lib/dependency-factory.hpp

@@ -91,7 +91,13 @@ namespace lib {
       void*
       buildInstance()
         {
-          REQUIRE (ctorFunction_);
+          if (!ctorFunction_)
+            throw error::Fatal ("lib::Depend: attempt to retrieve a service object prior to initialisation "
+                                "of the DependencyFactory. Typically, this happens due to a misconfiguration "
+                                "regarding static initialisation order. When lib::Depend<TY> is placed into "
+                                "a class static variable, then the definition and initialisation of that "
+                                "variable must happen prior to the call which caused this exception."
+                               ,error::LUMIERA_ERROR_LIFECYCLE);
           return ctorFunction_();
         }