Refactor needs_sphinx

sphinx/application.py

@@ -133,12 +133,14 @@ class Sphinx(object):
         self.config.check_unicode(self.warn)
         # defer checking types until i18n has been initialized
 
+        # initialize some limited config variables before loading extensions
+        self.config.pre_init_values(self.warn)
+
         # check the Sphinx version if requested
-        needs_sphinx = self.config.get_needs_sphinx()
-        if needs_sphinx and needs_sphinx > sphinx.__display_version__:
+        if self.config.needs_sphinx and self.config.needs_sphinx > sphinx.__display_version__:
             raise VersionRequirementError(
                 'This project needs at least Sphinx v%s and therefore cannot '
-                'be built with this version.' % needs_sphinx)
+                'be built with this version.' % self.config.needs_sphinx)
 
         # set confdir to srcdir if -C given (!= no confdir); a few pieces
         # of code expect a confdir to be set

sphinx/config.py

@@ -338,9 +338,11 @@ class Config(object):
                      'characters; this can lead to Unicode errors occurring. '
                      'Please use Unicode strings, e.g. %r.' % (name, u'Content'))
 
-    def get_needs_sphinx(self):
-        """Obtain the value of ``needs_sphinx``"""
-        return self.overrides.get('needs_sphinx') or self._raw_config.get('needs_sphinx')
+    def pre_init_values(self, warn):
+        """Initialize some limited config variables before loading extensions"""
+        variables = ['needs_sphinx']
+        for name in variables:
+            self.__dict__[name] = self.overrides.get(name) or self._raw_config.get(name)
 
     def init_values(self, warn):
         config = self._raw_config