Prefabs in git

I haven't seen exactly that problem, but if you're not vigilant with your use of the "File/Save Project" menu option, you can see similar symptoms, and this could be what happened to you.

In more detail, when you modify a prefab (e.g. press the "apply" button while editing it in a scene) Unity just caches the change in memory, and doesn't write it to disk yet. This is true for some other asset types too, such as ScriptableObjects.

So before checking into version control you must make sure you execute "File/Save Project" in Unity, which flushes these changed assets to disk - and also save the scene, of course, which does not generally happen automatically at any point.

If you don't do that then you can sometimes get symptoms like those you saw when later on Unity does write the prefab file to disk, e.g.:

1) you clone the repository 2) you create some prefabs, place instances in a scene 3) you modify and apply the prefab changes, but don't save the project 4) you commit the modified scene file and prefab files to the repository 5) time passes, you close Unity, open it again, edit unrelated files 6) you go to commit some new changes and now the prefabs are showing up as modified

The problem here is that the prefab changes from (3) were not saved to disk ready for the commit in (4). So the commit in (4) contained stale data.

The prefab files were saved at some point during (5), e.g. when I closed Unity or opened a different project. So now git shows them as modified.

So, this may not be what is happening for you, but I wanted to make it clear that if you're not vigilant with use of "Save Project" before committing changes, then you can see very similar symptoms, and it could be what happened in your case.

Something else you can do to track these problems is use text-based asset serialization (if you're Pro users) - then you stand some chance of being able to analyse the changes that git is reporting, and figure out where they might come from.

thanks for your reply :)

I understood how unity saves our prefabs. but even when I do "Save Project" git marks prefabs as changed. another strange thing that diff shows that prefab is unmodified. that is : git sees prefab as modified, but diff says that it's not.

and we're already using text-based serialization

There must be some difference or git would not claim to see one. Is it a CRLF issue perhaps?

agreed.

source tree shows that nothing is changed "unmodified file", but git says that this file is modified. take a look

Has anyone discovered a cause or solution to this problem? We're getting the exact same thing, using unity 5.3.3

I've tried searching around, but this seems to be the only post on the topic.