I run a few systems using all pkgsrc for "every" component of an operating
system. I do not have a "which" command, so every once in awhile some
package breaks -- but it has only been a couple times out of hundreds of
packages used. (For example, I provide a patches to the gramps project
because it used "which".)

   Jeremy C. Reed
   http://bsd.reedmedia.net/