Return early in VersionControl.check_destination() if no prompt.

src/pip/_internal/vcs/__init__.py

@@ -301,8 +301,6 @@ class VersionControl(object):
         if not os.path.exists(dest):
             return True
 
-        checkout = False
-        prompt = False
         rev_display = rev_options.to_display()
         if os.path.exists(os.path.join(dest, self.dirname)):
             existing_url = self.get_url(dest)
@@ -322,9 +320,9 @@ class VersionControl(object):
                     )
                     self.update(dest, rev_options)
                 else:
-                    logger.info(
-                        'Skipping because already up-to-date.')
-            else:
+                    logger.info('Skipping because already up-to-date.')
+                return False
+
             logger.warning(
                 '%s %s in %s exists with URL %s',
                 self.name,
@@ -343,15 +341,14 @@ class VersionControl(object):
             )
             prompt = ('(i)gnore, (w)ipe, (b)ackup ', ('i', 'w', 'b'))
 
-        if prompt:
         logger.warning(
             'The plan is to install the %s repository %s',
             self.name,
             url,
         )
-            response = ask_path_exists('What to do?  %s' % prompt[0],
-                                       prompt[1])
+        response = ask_path_exists('What to do?  %s' % prompt[0], prompt[1])
 
+        checkout = False
         if response == 's':
             logger.info(
                 'Switching %s %s to %s%s',
@@ -377,6 +374,7 @@ class VersionControl(object):
             checkout = True
         elif response == 'a':
             sys.exit(-1)
+
         return checkout
 
     def unpack(self, location):