Merge pull request #1832 from ogayot/variation-bug

Fix crash when switching sources having different variations

examples/answers/desktop.yaml

@@ -1,4 +1,4 @@
-#source-catalog: examples/sources/desktop.yaml
+#source-catalog: examples/sources/desktop-standard.yaml
 Source:
   source: ubuntu-desktop
 Welcome:

examples/sources/desktop-standard.yaml

@@ -0,0 +1,29 @@
+- default: true
+  description:
+    en: A full featured Ubuntu Desktop.
+  id: ubuntu-desktop
+  locale_support: langpack
+  name:
+    en: Ubuntu Desktop
+  path: standard.squashfs
+  preinstalled_langs:
+  - de
+  - en
+  - es
+  - fr
+  - it
+  - pt
+  - ru
+  - zh
+  - ''
+  size: 4033826816
+  type: fsimage-layered
+  variant: desktop
+  variations:
+    enhanced-secureboot:
+      path: standard.enhanced-secureboot.squashfs
+      size: 4336062464
+      snapd_system_label: enhanced-secureboot-desktop
+    standard:
+      path: standard.squashfs
+      size: 4033826816

examples/sources/desktop.yaml

@@ -1,11 +1,11 @@
 - default: true
   description:
-    en: A full featured Ubuntu Desktop.
-  id: ubuntu-desktop
+    en: A minimal but usable Ubuntu Desktop.
+  id: ubuntu-desktop-minimal
   locale_support: langpack
   name:
-    en: Ubuntu Desktop
-  path: standard.squashfs
+    en: Ubuntu Desktop (minimized)
+  path: minimal.squashfs
   preinstalled_langs:
   - de
   - en
@@ -16,14 +16,42 @@
   - ru
   - zh
   - ''
-  size: 4033826816
+  size: 4015337472
+  type: fsimage-layered
+  variant: desktop
+  variations:
+    minimal:
+      path: minimal.squashfs
+      size: 4015337472
+    minimal-enhanced-secureboot:
+      path: minimal.enhanced-secureboot.squashfs
+      size: 4319010816
+      snapd_system_label: enhanced-secureboot-desktop
+- description:
+    en: A full featured Ubuntu Desktop.
+  id: ubuntu-desktop
+  locale_support: langpack
+  name:
+    en: Ubuntu Desktop
+  path: minimal.standard.squashfs
+  preinstalled_langs:
+  - de
+  - en
+  - es
+  - fr
+  - it
+  - pt
+  - ru
+  - zh
+  - ''
+  size: 5735194624
   type: fsimage-layered
   variant: desktop
   variations:
     enhanced-secureboot:
-      path: standard.enhanced-secureboot.squashfs
-      size: 4336062464
+      path: minimal.standard.enhanced-secureboot.squashfs
+      size: 6006235136
       snapd_system_label: enhanced-secureboot-desktop
     standard:
-      path: standard.squashfs
-      size: 4033826816
+      path: minimal.standard.squashfs
+      size: 5735194624

subiquity/server/controllers/filesystem.py

@@ -404,6 +404,7 @@ class FilesystemController(SubiquityController, FilesystemManipulator):
         return info
 
     async def _examine_systems(self):
+        self._variation_info.clear()
         catalog_entry = self.app.base_model.source.current
         for name, variation in catalog_entry.variations.items():
             system = None

subiquity/server/controllers/tests/test_filesystem.py

@@ -369,6 +369,36 @@ class TestSubiquityControllerFilesystem(IsolatedAsyncioTestCase):
             await self.fsc._pre_shutdown()
         mock_run.assert_called_once_with(["mountpoint", "/target"])
 
+    async def test_examine_systems(self):
+        # In LP: #2037723 and other similar reports, the user selects the
+        # source 'ubuntu-desktop-minimal' first and then switches to
+        # 'ubuntu-desktop'. The variations of those two sources are different.
+        # Upon switching to the new source, we forgot to discard the old
+        # variations. This lead to a crash further in the install.
+        self.fsc.model = model = make_model(Bootloader.UEFI)
+        make_disk(model)
+        self.app.base_model.source.current.type = "fsimage"
+        self.app.base_model.source.current.variations = {
+            "minimal": CatalogEntryVariation(path="", size=1),
+        }
+
+        self.app.dr_cfg = DRConfig()
+        self.app.dr_cfg.systems_dir_exists = True
+
+        await self.fsc._examine_systems()
+
+        self.assertEqual(len(self.fsc._variation_info), 1)
+        self.assertEqual(self.fsc._variation_info["minimal"].name, "minimal")
+
+        self.app.base_model.source.current.variations = {
+            "default": CatalogEntryVariation(path="", size=1),
+        }
+
+        await self.fsc._examine_systems()
+
+        self.assertEqual(len(self.fsc._variation_info), 1)
+        self.assertEqual(self.fsc._variation_info["default"].name, "default")
+
 
 class TestGuided(IsolatedAsyncioTestCase):
     boot_expectations = [