looper report messaging

[nsheff]

looper report happily created an empty report for me:

looper report --portable
Looper version: 2.0.0a2
Command: report
Using looper config (.looper.yaml).
No config key in Project, or reading project from dict
Portable flag set: True
Building index page for pipeline: PEPATAC
Creating objects summary
'PEPATAC' pipeline stats summary (n=1): /project/shefflab/brickyard/results_pipeline/.../PEPATAC_stats_summary.tsv
'PEPATAC' pipeline objects summary (n=0): /project/shefflab/brickyard/results_pipeline/.../PEPATAC_objs_summary.yaml
 * Creating sample pages
 * Creating object pages
Report zip file successfully created: /project/shefflab/brickyard/results_pipeline/.../portable_reports/PEPATAC_report_portable
Report directory: /project/shefflab/brickyard/results_pipeline/.../portable_reports/PEPATAC/index.html
Portable flag set: True
Building index page for pipeline: PEPATAC
Creating objects summary
'PEPATAC' pipeline stats summary (n=1): /project/shefflab/brickyard/results_pipeline/.../PEPATAC_stats_summary.tsv
'PEPATAC' pipeline objects summary (n=0): /project/shefflab/brickyard/results_pipeline/.../PEPATAC_objs_summary.yaml
 * Creating sample pages
 * Creating object pages
Report zip file successfully created: /project/shefflab/brickyard/results_pipeline/.../portable_reports/PEPATAC_report_portable

...

I guess it couldn't find the samples or the stats or something. So, there needs to be some better checking to avoid just happily creating an empty report.

What should happen

instead of creating a report, I would expect it to say something like "no results found" with some helpful information about how my project may be misconfigured. It never really makes sense to produce an empty report with no records, I guess.