Change bases¶
A base snap is a special kind of snap that provides a runtime environment with a minimal set of libraries common to most applications. They’re transparent to users, but they need to be carefully considered when building a snap.
Each base snap is built from a corresponding Ubuntu LTS release. Migrating a snap from one base to the next gives the snap access to newer packages, extended support, and the latest Snapcraft features, including plugins and extensions.
The complexity of the migration process is directly linked to both dependencies in the snap’s project file and the base snap versions being migrated between.
At its simplest, migrating from one base snap to another requires only that the base
key is updated:
- base: core18
+ base: core20
But further changes will most likely be needed. These will depend on the original base and the packages that are bundled with the application.
Update from an old or absent base¶
Migrating a snap from having no base, or base: core, to core18 or core20,
for example, is a more involved process than going from core18 to core20.
This is because building a snap with an old base causes Snapcraft to operate in compatibility mode.
Compatibility mode is essentially an older (2.43-era) version of Snapcraft, and will lose the functionality of newer releases.
Core migration guides¶
Our core migration how-to guides provide detailed instructions and examples to help you transition your snap between specific bases.