Comment 5 for bug 1715399

Before this update lands in the -update pockets, the following tests need to pass:

Container builds:

 * Clean the project without arguments:

     `SNAPCRAFT_CONTAINER_BUILDS=1 snapcraft clean`

Plugins:

 * Build a snap with the catkin plugin.
 * Build a snap with the jhbuild plugin.

Errors:

 * Try to build a snap without mksquashfs.

Exploratory:

 * Use build-snaps to build snaps.
 * Build the same snap multiple times, to check the caching.
 * Build snaps with the nodejs plugin and yarn.
 * Build snaps with SNAPCRAFT_CONTAINER_BUILDS=1 using local and remote LXD.
 * Build snaps with SNAPCRAFT_BUILD_INFO=1, check the manifest.yaml in the prime/snap directory.
 * Try to get as many errors as possible, check the error messages or the trace returned when running with `--debug`.
 * Build snaps with grammar in build and stage packages.