traceback in simplestreams when release folder doesn't exist

[Brian Murray]

We ran into a Traceback when working on the Kinetic Beta release and running the following command:

ARCHES='amd64' for-project ubuntustudio publish-release dvd 20220928.1 dvd named beta

Traceback (most recent call last):
  File "/home/cdimage/bin/publish-release", line 62, in <module>
    main()
  File "/home/cdimage/bin/publish-release", line 58, in main
    publisher.publish_release(source, date, publish_type)
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/tree.py", line 3722, in publish_release
    self.refresh_simplestreams()
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/tree.py", line 1816, in refresh_simplestreams
    sstreams.generate()
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/simplestreams.py", line 228, in generate
    self.scan_tree()
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/simplestreams.py", line 342, in scan_tree
    self.scan_releases_project(project_dir, entry)
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/simplestreams.py", line 327, in scan_releases_project
    self.scan_target(target_dir, series, project, None, None)
  File "/srv/cdimage.ubuntu.com/bin/../lib/cdimage/simplestreams.py", line 182, in scan_target
    for file in os.listdir(target_dir):
FileNotFoundError: [Errno 2] No such file or directory: '/srv/cdimage.ubuntu.com/www/full/ubuntu/releases/kinetic/release'

I worked around it with the following cowboy as I didn't think we should have a release directory.

cdimage@ancientminister:~/cdimage$ bzr diff lib/cdimage/simplestreams.py
=== modified file 'lib/cdimage/simplestreams.py'
--- old/lib/cdimage/simplestreams.py 2021-10-21 14:17:18 +0000
+++ new/lib/cdimage/simplestreams.py 2022-09-29 23:57:30 +0000
@@ -321,9 +321,10 @@
                 # TODO: let's log this and continue
                 continue
             target_dir = os.path.join(releases_dir, entry, "release")
- # The image ID is the point version for now, since those should
- # be unique. This might still be up for discussion.
- self.scan_target(target_dir, series, project, None, None)
+ if os.path.exists(target_dir):
+ # The image ID is the point version for now, since those should
+ # be unique. This might still be up for discussion.
+ self.scan_target(target_dir, series, project, None, None)

     def scan_tree(self):
         """Scan all releases/ directories on cdimage."""