I just followed the tutorial to setup Nutch from NutchWiki.
Downloaded Nutch 2.x src and set all configurations.
The problem occurs when I just started to crawl.
When I run this code :
bin/nutch inject crawl/crawldb urls
Unrecognized arg urls
I was going through the same problem. The documentation seems to be outdated. It is for 1.x .
For 2.x I have tried the following and it worked for me.
bin/nutch inject urls
Hope it helps.