camera tracker permanently stuck on 'solving camera' no indication of how long left
this is for a 30 second clip filmed with a DSLR hand held , a litte bit of shake and some panning, and walking
Yes, some shots just won't solve. Try trimming the shot so it's shorter. 30 seconds is an eternity. I just cut a :30 second TV spot that has 12 edits in the action. The average shot length in a movie has gone from about 12 seconds in the 1930's to about 3 seconds today. Data From a Century of Cinema Reveals How Movies Have Evolved
The normal procedure for working on a camera tracked shot is to rough cut it to approximately the finished shot length plus a few frames as handles, then do the camera tracking and insert your effects. If you really must camera track a shot that is longer than just a few seconds you'll have to carefully plan and shoot the shot so the camera can be recreated. The longer the shot the more likely it is that the software cannot come solve for the camera. The more things that are moving in the shot the less likely it is that you'll get a good solution. For example, if you walk with a camera down a busy sidewalk in New York city for thirty seconds you probably will not be able to solve for the camera unless you mask out all of the moving people and then pre-compose the shot before you try and solve it.
A DSLR that is moving around quite a bit will also have rolling shutter problems and that will foul up the shot. Motion blur from quick movements will also foul up the solution. There is no camera tracker that can solve all shots. AE's Camera Tracker does a reasonably good job with carefully shot footage that has a lot of fixed geometry in the scene when the lens used has very little lens distortion. Without seeing your shot this is the best I can come up with. The chance of it being the shot instead of a bug is very high.