Fix @cachable decorator for windows.

[euronion]

For windows paths, this returned e.g. "C" (for paths like "C:\Temp\vresutils") which is an invalid input for os.stat.

IMHO: How could this ever have worked?

[coroa]

If you want to use cachable on windows, you have to take out or at least make all of the permission handling optional; ie.

https://github.com/FRESNA/vresutils/blob/master/vresutils/decorators.py#L70-L75
should be skipped on windows, as well as

vresutils/vresutils/decorators.py

Lines 157 to 158 in c8ed491

	if gid: os.fchown(f.fileno(), -1, gid)
	if mode: os.fchmod(f.fileno(), mode)

[coroa]

Suggested change

	st = os.stat(root_dir(cache_dir))
	st = os.stat(cache_dir)

[coroa]

The code in the if enable clause was supposed to get the unix permissions of the cache directory, so that later on we can set the same permissions on the cache files.

I mistakenly introduced the [0] back when I added the fallback_cache_dirs (80c9997). In some intermediate state cache_dir was a list of cache directories and then you wanted the first one from the list.

[euronion]

TBH I did not time looking into what this function does nor did I use it intentionally. My snakemake workflow in pypsa-eur just failed because of this during some work on my windows machine and I needed a quick fix.

If I understand you correctly, this code shouldn't have been called on my windows machine?

[coroa]

The default should have been to just shut up, if the cache_dir directory, which you configure in your .vresutils.config does not exist. Maybe just remove or comment that particular line from your config. Then it should ignore all cachable stuff.

If you don't have any .vresutils.config it should also just work.

[euronion]

I was expecting it to work out-of-the-box as you describe it.

If you don't have any .vresutils.config it should also just work.

Mea culpa. Somehow somewhen I created this file causing the problem.
Deleting it resolves the problem.

Thanks a lot for the hint. From my side we can close w/o merge.