As per https://snapcraft.io/docs/snap-layouts,
bind-mounts significantly increase the startup time of the snap.
Use symlinks instead for better performance.
This prevents the config and the user collection from being
backed up by snapd on update. If the user reverts qelectrotech,
the current collection will thus not be overwritten by the
possibly outdated backup.
Add a migration script that automatically transfers the user's .qet
directory to the new location.
The kde-neon extension reduces our boilerplate in snapcraft.yaml
and reduces the snap size considerably, as we do not need to ship
any library that is already included in the kde-frameworks-5-core18
snap itself.
This limits qelectrotech builds to the architectures supported
by kde-frameworks-5-core18, i.e. only amd64.
Snapcraft can find its build recipes in 2 places:
* a snap/ directory at the top of the sources;
* a build-aux/snap/ directory, since Snapcraft 3.3;
This commit moves from the former to the latter, so that we can group
all the packaging recipes together.
