There have been observations at snap runtime that some snaps might have an improved startup time if the squash FS compression was changed.
This document defines how this experimental feature must work.
Enablement of the features depends on swapping Snapcraft’s use of mksquashfs to the snap pack command.
Snapcraft’s snapcraft.yaml shall accept a new top-level entry compression
with two valid values: lzo and xz (the current default).
If this key is used without Enabling the feature a standard schema error shall be displayed:
Issues while validating snapcraft.yaml: Additional properties are not allowed ('compression' was unexpected)When used with the feature enabled, the following message shall be displayed during the packing step:
EXPERIMENTAL: Setting the squash FS compression to 'lzo'.