Intermittent CI failure: install-on-tty OSError: [Errno 39] Directory not empty: '.git'

[awelzel]

The test failed after a merge to master, but a re-run fixed it.. This is for record keeping in case it happens again.

https://cirrus-ci.com/task/4539628506578944?logs=test#L1

ci/test.sh
[#2] tests.install-on-tty ... failed
  % 'bash /tmp/cirrus-ci-build/testing/.tmp/tests.install-on-tty/install-on-tty' failed unexpectedly (exit code 1)
  % cat .stderr
  Switched to a new branch 'main'
  Switched to a new branch 'drop-corge'
  Switched to branch 'master'
  warning: skipped using package source named "one": failed to clone git repo
  error: package "foo" is not installed
  Traceback (most recent call last):
    File "/tmp/cirrus-ci-build/testing/../zkg", line 3040, in <module>
      main()
    File "/tmp/cirrus-ci-build/testing/../zkg", line 3036, in main
      args.run_cmd(manager, args, config, configfile)
    File "/tmp/cirrus-ci-build/testing/../zkg", line 626, in cmd_install
      package_info = manager.info(name, version=version, prefer_installed=False)
    File "/tmp/cirrus-ci-build/zeekpkg/manager.py", line 1770, in info
      return self._info(package, status, version)
    File "/tmp/cirrus-ci-build/zeekpkg/manager.py", line 1786, in _info
      clone = _clone_package(package, clonepath, version)
    File "/tmp/cirrus-ci-build/zeekpkg/manager.py", line 3206, in _clone_package
      delete_path(clonepath)
    File "/tmp/cirrus-ci-build/zeekpkg/_util.py", line 51, in delete_path
      shutil.rmtree(path)
    File "/usr/lib64/python3.6/shutil.py", line 486, in rmtree
      _rmtree_safe_fd(fd, path, onerror)
    File "/usr/lib64/python3.6/shutil.py", line 428, in _rmtree_safe_fd
      onerror(os.rmdir, fullname, sys.exc_info())
    File "/usr/lib64/python3.6/shutil.py", line 426, in _rmtree_safe_fd
      os.rmdir(name, dir_fd=topfd)
  OSError: [Errno 39] Directory not empty: '.git'

1 of 43 tests failed