Coverage 0 but reads found
Hi,
Thanks for this tool, I use it frequently. I have found one case though where mosdepth outputs coverage 0 for a region of interest but I see reads on IGV. I then subset the BAM file to my region of interest (chrY:12000000-12100000)  and running mosdepth on the subset does give me the expected output (with coverage between 40 and 50). The command used was:
`mosdepth -n --fast-mode --by 500 test test.bam` (with
 -t 4 for the full BAM). Mosdepth version is 0.3.1.  Any idea why this could happen? I attach the bed output (sliced for the region of interest) in both cases, do let me know if I can send something else. 
[full.regions.bed.gz](https://github.com/brentp/mosdepth/files/7122037/full.regions.bed.gz)
[subset.regions.bed.gz](https://github.com/brentp/mosdepth/files/7122040/subset.regions.bed.gz)

Thanks,
Jose