Unable to open cache files on MacOS

[TomonobuTsujikawa]

On MacOS environment, it seems that dataset caches may be removed by other process. Therefore, training fails.

2025-01-01 00:00:00,000 [nnabla]: Using context "Context(backend=['cpu:float'], array_class='CpuCachedArray', device_id='')"
NNabla command line interface (Version:1.40.0.dev1, Build:241118024755, Callback:10.2.0)
Cannot open /var/folders/hogehoge/10012.cache/original.csv
Cannot open /var/folders/hogehoge/10012.cache/order.csv
(snip)
2025-01-01 00:00:00,000 [worker]: [ERROR]: console_cli command is failed.

[TomonobuTsujikawa]

As a short-term solution, you can select the Dataset from the left pane of NNC-Desktop, delete the target dataset once,
and then re-import the dataset to regenerate the cache.
(In the current version of NNC-Desktop, datasets are copied to the nncd_bucket directory, so the original dataset will not be deleted.)
However, I think the same issue may occur again after a few days.

For a permanent solution, we plan to change the location where the cache directory is created.