As discussed on the forum, scriptlets should run with the "-e" shell flag (i.e. fail if any command returns non zero): https://forum.snapcraft.io/t/scripting-and-setting-metadata-in-snapcraft/1447/2?u=jamesh At the moment, if I put something like the following in my snapcraft.yaml, the build will succeed: install: | command_that_fails command_that_succeeds Execution continues past the first failed command, and the second successful command causes the scriptlet to return 0. Situations like this almost always indicate a bug, and for the cases where the exit code should be ignored there are work arounds (e.g. run "set +e", or append "||:" to the end of the command).