wily's temp files seem to sometimes conflict with git checkout

[brad-engel]

Describe the bug
wily build crashes every time it checks out a specific commit in my history with message "Updating the following directories would lose untracked files in them". Before running wily there were no untracked files, and after this crash the only untracked files in my git / code directory were the ones placed there by wily.

To Reproduce
Steps to reproduce the behavior:
I'm not sure how to recreate the conditions, but this happens every time wily build hits a specific commit in my project's history. I'm not sure what is special about that commit.

Expected behavior
wily build completes without crashing

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: macos 11.3
• Browser N/A

Additional context
There were no untracked files in this directory before I ran wily. The only untracked files after this crash were wily temporary files within my git code directory. Note that adding these wily files to my .gitignore does not change the crash.

cmdline: git checkout 8db258e807690ad7b48fdca1d1f9a08daa178f78
stderr: 'error: Updating the following directories would lose untracked files in them:
mycode

Aborting''
Traceback (most recent call last):
File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.9/bin/wily", line 8, in
sys.exit(cli())
File "/usr/local/lib/python3.9/site-packages/click/core.py", line 829, in call
return self.main(*args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python3.9/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/wily/main.py", line 133, in build
build(
File "/usr/local/lib/python3.9/site-packages/wily/commands/build.py", line 209, in build
raise e
File "/usr/local/lib/python3.9/site-packages/wily/commands/build.py", line 110, in build
archiver.checkout(revision, config.checkout_options)
File "/usr/local/lib/python3.9/site-packages/wily/archivers/git.py", line 102, in checkout
self.repo.git.checkout(rev)
File "/usr/local/lib/python3.9/site-packages/git/cmd.py", line 545, in
return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/git/cmd.py", line 1011, in _call_process
return self.execute(call, **exec_kwargs)
File "/usr/local/lib/python3.9/site-packages/git/cmd.py", line 828, in execute
raise GitCommandError(command, status, stderr_value, stdout_value)
git.exc.GitCommandError: Cmd('git') failed due to: exit code(1)
cmdline: git checkout 8db258e807690ad7b48fdca1d1f9a08daa178f78
stderr: 'error: Updating the following directories would lose untracked files in them:
mycode

[tonybaloney]

Which files did it create? The wily cache should go into $HOME/.wily/HASH

Can you run the commands again with the --debug flags and share the output