Merge ~mwhudson/ubuntu-cdimage:preinstalled-certainty into ubuntu-cdimage:main

[Michael Hudson-Doyle]

assert that we do not run any preinstalled images through d-i

we do not build any images where live_fs_only(config) is false and
config["CDIMAGE_PREINSTALLED"] is true, and we sure as heck don't want
to start doing that by accident

[Steve Langasek (vorlon)]

review: Approve

diff --git a/lib/cdimage/build.py b/lib/cdimage/build.py
index 503102e..ea9c507 100644
--- a/lib/cdimage/build.py
+++ b/lib/cdimage/build.py
@@ -712,20 +712,20 @@ def build_image_set_locked(config, options):
         elif is_live_fs_only(config):
             build_livecd_base(config)
         else:
-            if not config["CDIMAGE_PREINSTALLED"]:
-                log_marker("Germinating")
-                germination = Germination(config)
-                germination.run()
+            assert not config["CDIMAGE_PREINSTALLED"]
 
-                log_marker("Generating new task lists")
-                germinate_output = germination.output(config.project)
-                germinate_output.write_tasks()
+            log_marker("Germinating")
+            germination = Germination(config)
+            germination.run()
 
-                log_marker("Checking for other task changes")
-                germinate_output.update_tasks(date)
+            log_marker("Generating new task lists")
+            germinate_output = germination.output(config.project)
+            germinate_output.write_tasks()
 
-            if (config["CDIMAGE_LIVE"] or config["CDIMAGE_SQUASHFS_BASE"] or
-                    config["CDIMAGE_PREINSTALLED"]):
+            log_marker("Checking for other task changes")
+            germinate_output.update_tasks(date)
+
+            if (config["CDIMAGE_LIVE"] or config["CDIMAGE_SQUASHFS_BASE"]):
                 log_marker("Downloading live filesystem images")
                 download_live_filesystems(config)