My first question is about building EGit.
               Following the contributor guide instructions, I managed to build JGit and
                EGit with maven 3.
               JGit build succeds, but EGit build fails. Unit
                tests pass, but several UI tests (swtbot)
                break.
            (I'm
                first building the unmodified EGit
                code from master branch. I use
                maven 3.0.3 in a Cygwin bash console.)
                
              Question #1: Should I care about
                those failures ? Or are they OK ?
               
        
         
        in general all tests should pass, but UI tests sometimes
          are a bit brittle, so unfortunately
        sometimes it's necessary to run the UI tests multiple times
          until they succeed. We constantly
        try to improve this but this doesn't come for free ... 
        
        
        
            My second question
                is about testing my modified version of EGit.
                The Contributor Guide only tells about
                a testing instance at eclipse.org.
            
                Question #2: Is it possible for me to test locally ?
                Do you have any document URL where I would understand
                how to proceed ?
                Or is the use of a testing instance at eclipse.org mandatory ?
               
        
         
        in order to run UI tests locally you need to have swtbot
          installed as described
        in the contributor guide. Then simply select the test class
          or method and
        click "Run As > SwtBot Test". This should start the test
          locally. Beware: don't
        click around when a UI test is running as this may disturb
          the UI test by e.g.
        moving the focus to another window. I updated the
          contributor guide
        accordingly.