2.43 breaks when you run "snapcraft pull" first

[Christopher Lee]

Juju snap builds fail with snapcraft 2.43 with the error message (full build log[1]):

"""
Skipping pull juju (already ran)
Failed to reuse files from previous run: The 'pull' step of 'wrappers' is out of date:
The source has changed on disk.
To continue, clean that part's 'pull' step by running `snapcraft clean wrappers -s pull`.
Build failed
"""

This is build via: https://code.launchpad.net/~juju-qa-bot/+snap/juju-edge

[1] https://launchpadlibrarian.net/387706899/buildlog_snap_ubuntu_xenial_arm64_juju-edge_BUILDING.txt.gz

[Adam Collard (adam-collard)]

We hit this in the snap store proxy too, the fix was to add 'source-type: git' to the parts that used the 'dump' plugin.

[Adam Collard (adam-collard)]

https://github.com/snapcore/snapcraft/pull/2256

[Kyle Fazzari (kyrofa)]

This is the culprit:

> wrappers:
> plugin: dump
> source: snap/

Snapcraft needs to own the snap directory. It's meant for the snapcraft.yaml, plugins, hooks, icons, desktop files, and snapcraft writes a cache into it. It's not meant for part sources (and the next snapcraft release will begin warning about using it in this manner). The cache is what is making your part out of date. A quick workaround is to move that part's source out of the snap directory. This issue is a dupe of a bug that is Fix Committed, so while this will begin working again in the next release, we still do not recommend using the snap/ directory for part sources.