This is easier said than done, unfortunately. Testing every possible case would take a lot of time, indeed.
The problem is not that much on Haiku side, actually. The Haiku project always had high standards as to what gets included, and the devs are generally careful about what they do (breakage do happen occasionally, unfortunately). The situation even improved with Gerrit, as we now have an area where we can store work-in-progress code and benefit from peer review on it.
Where we are getting more problems currently is on HaikuPorts side. HaikuPorts has adopted a much more open policy (anyone can submit pull request on github), and while they do perform review to ensure submitted recipes look and work fine, they tend to do little testing of the results.
This is understandable as the project has started to gain traction only quite recently, and does not have the same culture as Haiku - after all, they never made a release of any kind there.
Currently, the Haiku package repos are populated straight from haikuports master branch, which means such problems land directly into the user systems. This is not acceptable by Haiku standard, and it is one of the last few things we need to solve before we get a beta out. Either by having haikuports improving their testing requirements before they merge things, or by somehow creating a “stable” packet repository for our releases.