Adding busybox to a snap with the following yaml triggers an error on snapcraft 2.9. Yaml: name: taskwarrior-jamiebennett version: 2.5.1 summary: Taskwarrior manages your TODO list from the command line. description: Taskwarrior is Free and Open Source Software that manages your TODO list from the command line. It is flexible, fast, and ubobtrusive. It does its job then gets out of your way. confinement: devmode # use "strict" to enforce system access only via declared interfaces build-packages: [libc6, libgcc1, libgnutls-dev, libstdc++6, uuid-dev] apps: taskwarrior: command: task busybox: command: sh parts: taskwarrior: plugin: cmake make-parameters: - -DCMAKE_BUILD_TYPE=release . source: https://taskwarrior.org/download/task-2.5.1.tar.gz busybox: plugin: nil stage-packages: - busybox Error: jtar: Exiting with failure status due to previous errors dpkg-deb: error: subprocess tar returned error exit status 2 Traceback (most recent call last): File "/usr/lib/python3/dist-packages/snapcraft/internal/repo.py", line 179, in unpack subprocess.check_call(['dpkg-deb', '--extract', pkg, rootdir]) File "/usr/lib/python3.5/subprocess.py", line 581, in check_call raise CalledProcessError(retcode, cmd) subprocess.CalledProcessError: Command '['dpkg-deb', '--extract', '/media/jamie/UNTITLED/development/snaps/taskwarrior/parts/busybox/ubuntu/download/gcc-6-base_6.0.1-0ubuntu1_amd64.deb', '/media/jamie/UNTITLED/development/snaps/taskwarrior/parts/busybox/install']' returned non-zero exit status 2 During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/bin/snapcraft", line 31, in <module> snapcraft.main.main() File "/usr/lib/python3/dist-packages/snapcraft/main.py", line 146, in main return run(args, project_options) File "/usr/lib/python3/dist-packages/snapcraft/main.py", line 193, in run lifecycle.snap(project_options, args['<directory>'], args['--output']) File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle.py", line 242, in snap snap = execute('strip', project_options) File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle.py", line 84, in execute _Executor(config, project_options).run(step, part_names) File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle.py", line 113, in run self._run_step(step, part, part_names, dirty, recursed) File "/usr/lib/python3/dist-packages/snapcraft/internal/lifecycle.py", line 148, in _run_step getattr(part, 'prepare_{}'.format(step))() File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler.py", line 264, in prepare_pull self._unpack_stage_packages() File "/usr/lib/python3/dist-packages/snapcraft/internal/pluginhandler.py", line 258, in _unpack_stage_packages self.ubuntu.unpack(self.installdir) File "/usr/lib/python3/dist-packages/snapcraft/internal/repo.py", line 181, in unpack raise UnpackError(pkg) snapcraft.internal.repo.UnpackError: /media/jamie/UNTITLED/development/snaps/taskwarrior/parts/busybox/ubuntu/download/gcc-6-base_6.0.1-0ubuntu1_amd64.deb