ci/nur/combine.py: Try to fix File exists: 'lib' error

[Rhys-T]

Followup to #762.

I don't know how I thought my changes in #762 were working on my machine. I really did try to test it, but I just noticed that the last couple of update_nur jobs failed with this error:

Traceback (most recent call last):
  File "/nix/store/jixljq3pr9zfyxvn1bz4r7h49awh00lc-nur/bin/.nur-wrapped", line 9, in <module>
    sys.exit(main())
  File "/nix/store/jixljq3pr9zfyxvn1bz4r7h49awh00lc-nur/lib/python3.10/site-packages/nur/__init__.py", line 63, in main
    args.func(args)
  File "/nix/store/jixljq3pr9zfyxvn1bz4r7h49awh00lc-nur/lib/python3.10/site-packages/nur/combine.py", line 175, in combine_command
    setup_combined()
  File "/nix/store/jixljq3pr9zfyxvn1bz4r7h49awh00lc-nur/lib/python3.10/site-packages/nur/combine.py", line 162, in setup_combined
    shutil.copytree(str(ROOT.joinpath("lib")), manifest_lib, symlinks=True)
  File "/nix/store/412d25bdawy2idxfpnis8vjcm8cz2ag7-python3-3.10.11/lib/python3.10/shutil.py", line 559, in copytree
    return _copytree(entries=entries, src=src, dst=dst, symlinks=symlinks,
  File "/nix/store/412d25bdawy2idxfpnis8vjcm8cz2ag7-python3-3.10.11/lib/python3.10/shutil.py", line 457, in _copytree
    os.makedirs(dst, exist_ok=dirs_exist_ok)
  File "/nix/store/412d25bdawy2idxfpnis8vjcm8cz2ag7-python3-3.10.11/lib/python3.10/os.py", line 225, in makedirs
    mkdir(name, mode)
FileExistsError: [Errno 17] File exists: 'lib'

I think this pull is the correct fix - passing dirs_exist_ok=True should make shutil.copytree overwrite existing files and reuse existing directories, mimicking its distutils counterpart more closely. But I clearly don't know how to test it properly. Can you offer any guidance on this, so I can avoid causing any more problems like this in the future?

Sorry for breaking things.

[Rhys-T]

If this doesn't work, I'd suggest just reverting #762 to get NUR working again until we can figure out how to fix this properly. I think the old script was working for most users - it was just Darwin/macOS where it was failing.

[Mic92]

@mergify queue

[mergify]

queue

✅ The pull request has been merged automatically

The pull request has been merged automatically at 1ec6e1a

[Mic92]

Also see #755