diff -Nuar "$1" "$2" 
--- ubiquity.orig/scripts/install.py	2016-05-11 14:58:57.503808383 +0200
+++ ubiquity/scripts/install.py	2016-05-11 15:22:29.231843935 +0200
@@ -133,6 +133,7 @@
                     preexec_fn=subprocess_setup)
             try:
                 self.copy_all()
+                self.run_target_post_hooks()
             except EnvironmentError as e:
                 if e.errno in (errno.ENOENT, errno.EIO, errno.EFAULT,
                                errno.ENOTDIR, errno.EROFS):
@@ -727,6 +728,28 @@
                     not misc.execute('losetup', '-d', dev)):
                 raise install_misc.InstallStepError(
                     "Failed to detach loopback device %s" % dev)
+    def run_target_post_hooks(self):
+        """Run hook scripts from /usr/lib/ubiquity/target-postconfig. This allows
+        casper to hook into us and repeat bits of its configuration in the
+        target system."""
+
+        hookdir = '/usr/lib/ubiquity/target-postconfig'
+
+        if os.path.isdir(hookdir):
+            # Exclude hooks containing '.', so that *.dpkg-* et al are avoided.
+            hooks = filter(lambda entry: '.' not in entry, os.listdir(hookdir))
+            self.db.progress('START', 0, len(hooks), 'ubiquity/install/title')
+            self.db.progress('INFO', 'ubiquity/install/target_hooks')
+            for hookentry in hooks:
+                hook = os.path.join(hookdir, hookentry)
+                if not os.access(hook, os.X_OK):
+                    self.db.progress('STEP', 1)
+                    continue
+                # Errors are ignored at present, although this may change.
+                subprocess.call(['log-output', '-t', 'ubiquity',
+                                 '--pass-stdout', hook])
+                self.db.progress('STEP', 1)
+            self.db.progress('STOP')
 
     def select_ecryptfs(self):
         """Is ecryptfs in use by an existing user? If so, keep it installed.