Bug reproduce instructions
---------------------------
1. git clone --branch=bug-20190410-guvcview https://github.com/Lin-Buo-Ren/snapcraft-bug-poc.git
2. cd snapcraft-bug-poc
3. snapcraft stage guvcview
Traceback
----------
```
Traceback (most recent call last):
File "/snap/snapcraft/2722/bin/snapcraft", line 11, in <module>
load_entry_point('snapcraft==3.3', 'console_scripts', 'snapcraft')()
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/cli/__main__.py", line 81, in run
run_snapcraft(prog_name="snapcraft")
File "/snap/snapcraft/2722/lib/python3.5/site-packages/click/core.py", line 722, in __call__
return self.main(*args, **kwargs)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/snap/snapcraft/2722/lib/python3.5/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/cli/lifecycle.py", line 251, in stage
_execute(steps.STAGE, parts, **kwargs)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/cli/lifecycle.py", line 126, in _execute
lifecycle.execute(step, project_config, parts)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/lifecycle/_runner.py", line 94, in execute
executor.run(step, part_names)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/lifecycle/_runner.py", line 148, in run
self._handle_step(part_names, part, step, current_step, cli_config)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/lifecycle/_runner.py", line 162, in _handle_step
getattr(self, "_run_{}".format(current_step.name))(part)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/lifecycle/_runner.py", line 226, in _run_stage
self._run_step(step=steps.STAGE, part=part, progress="Staging")
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/lifecycle/_runner.py", line 281, in _run_step
getattr(part, step.name)()
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/__init__.py", line 722, in stage
self._runner.stage()
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/_runner.py", line 84, in stage
"override-stage", self._override_stage_scriptlet, self._stagedir
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/_runner.py", line 137, in _run_scriptlet
scriptlet_name, function_call.strip()
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/_runner.py", line 193, in _handle_builtin_function
function(**function_args)
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/__init__.py", line 744, in _do_stage
fixup_func=fixup_func,
File "/snap/snapcraft/2722/lib/python3.5/site-packages/snapcraft/internal/pluginhandler/__init__.py", line 1097, in _migrate_files
os.remove(dst)
IsADirectoryError: [Errno 21] Is a directory: '/root/stage/usr/bin/X11'
```
Snapcraft
----------
Host: version 3.3+git17.g1b29058 from edge channel
Build environment: 3.3
Additional info
---------------
The `usr/bin/X11` symlink is shipped by x11-commons package, and for whatever reason points to `.`
