Logging from vcf_to_zarr

[jeromekelleher]

It would be useful if vcf_to_zarr wrote some debugging information to the Python log. It's a bit of a black box at the moment trying to figure out what's happening when things go wrong (which they do - we'll never cover all possible weirdly malformed VCF inputs).

[jeromekelleher]

Raising this one again - it really would be helpful to get some debug output when doing large VCF conversions. I'm very much flying blind trying to make a large VCF conversion work, and any output telling me what the process is actually doing would be helpful.

We can use the standard python logging infrastructure with Dask, right?

[benjeffery]

I think some logging could be added - but I'm not sure how much it would help as most of the work gets done in two big dask tasks. The most useful logs to me have been the dask worker logs and the dashboard.