Apologies for the incomplete bug report. snapcraft may return an error because of a problem with the snapcraft.yaml (for example bug 1578024), or it may fail for other reasons (for example bug 1624019) Evan says that currently, there is not a programmatic distinction (such as an error code) between these two kinds of error. This would be helpful in build.snapcraft.io, so that snapcraft.yaml-specific errors can be attached to the snapcraft.yaml UI.