hg view /bin/sh: hgk: command not found
I could not understand what going on. I enable hgk in /etc/mercurial/hgrc or ~/.hgrc. I specified the full path to hgk.py in there as well. I even modify default python path. It didn't work.
After some time of googling, changing various variables I found somewhere (probably on Mercurial page), that some Linux distro missing hgk even if they provide hgk.py. Now I know that Crux is one of them. I copied hgk from contrib directory in source package to /usr/bin and now hg view works fine.