This is the error shown when a script (previously known as scriptlet) fails:
Traceback (most recent call last):
File "/home/ubuntu/venv/snapcraft/bin/snapcraft", line 6, in <module>
exec(compile(open(__file__).read(), __file__, 'exec'))
File "/home/ubuntu/workspace/canonical/snapcraft/bin/snapcraft", line 36, in <module>
obj=dict(project=snapcraft.ProjectOptions()))
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 722, in __call__
return self.main(*args, **kwargs)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 1043, in invoke
return Command.invoke(self, ctx)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/decorators.py", line 17, in new_func
return f(get_current_context(), *args, **kwargs)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/cli/__init__.py", line 110, in run
ctx.forward(lifecyclecli.commands['snap'])
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 553, in forward
return self.invoke(cmd, **kwargs)
File "/home/ubuntu/venv/snapcraft/lib/python3.5/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/cli/lifecycle.py", line 132, in snap
project_options, directory=directory, output=output)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/lifecycle.py", line 349, in snap
execute('prime', project_options)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/lifecycle.py", line 130, in execute
_Executor(config, project_options).run(step, part_names)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/lifecycle.py", line 225, in run
self._run_step(step, part, part_names)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/lifecycle.py", line 262, in _run_step
getattr(part, step)()
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/pluginhandler/__init__.py", line 328, in build
script_runner.run(scriptlet=build_scriptlet)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/pluginhandler/_scriptlets.py", line 43, in run
run([scriptlet_path], cwd=self._builddir)
File "/home/ubuntu/workspace/canonical/snapcraft/snapcraft/internal/common.py", line 63, in run
subprocess.check_call(['/bin/sh', f.name] + cmd, **kwargs)
File "/usr/lib/python3.5/subprocess.py", line 581, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['/bin/sh', '/tmp/tmpsct8tq5m', '/tmp/tmpflw5zmz4']' returned non-zero exit status 1
That trace only mentions the temporary file where the script is copied and executed. It doesn't mention anything useful to understand the problem.
Lots of improvements are possible there. First, mention the script that causes the failure (i.e. prepare/build/install). Then, it's possible to show more than the exit status because stderr is likely to contain some useful details.
