While I program a lot I almost never use Java. So I have what I hope is a simple question about the tracker source: once I've downloaded it, what's the procedure to create (for instance) the installer on Mac?
The Tracker source code is for developers who are building new features for Tracker and is distributed so that developers can run Tracker from within Eclipse. Creating an installer for various operating systems is a difficult process and that requires software licenses, etc.
Well, I'd like to make a modification (a pretty simple one) and don't know the right way to then get that built. Even a jar file would be OK, if I can run it from that. I have Xcode already installed---is there some reason I can't just (with the right instructions) build an executable?
You should be able to do what you want by downloading the Tracker Eclipse Workspace (find link under For Developers on the Tracker home page). You'll have to install Eclipse if you don't already have it.
Launch Ecllipse and open the unzipped workspace (File|Switch Workspace|Other...). The Tracker version 4.61 source code is included and should compile automatically, but I recommend you download the version 4.72 source code (link also under For Developers) and replace the "src" folder in the Eclipse workspace with the vers 4.72 src folder You'll have to refresh the Eclipse project (hit the f5 key) for it to see the changes.
At this point you can make whatever code changes you wish with full debugging and testing within Eclipse. Once you have what you want, open the "build.xml" file in Eclipse (it's already in the workspace) and run the tracker_jar task by control-clicking it and choosing Run As|Ant Build. This will create the tracker.jar file you want.
I don't recommend you attempt to create your own installer. Just use the existing installer, then replace the tracker.jar in the Applications/Tracker.app/Contents/Resources/Java folder.
I hope this helps. Doug
PS If you make some interesting changes to Tracker, please let us know!