One crawl's status, progress and what it left out

One crawl: its status, pages read so far and coverage, what it did not read and why. Poll it after crawls_start until crawl.terminal is true; there is no estimated finish time. partial_budget and partial_blocked mean the crawl did not read the whole site, and a crawl that read 0 pages could not read the site: neither is a healthy site. coverage null means not measured (an old crawl, or one that never started), never that nothing was left out. Quote the crawl's figures as a claim about what it read. Next: when it is terminal, read what it found with issues_list.