Internally at <a href=">Acquia we had the need to add a custom plugin to our Solr 3.4 Build. This was already developed for Solr 1.4 but since Solr 3.x is using a very different approach while building and compiling its contrib folder this became a challenge.
I'll warn you because this is probably a very uncommon use-case for 90% of the users.

Normally the process of building Solr goes like this :

Get the source code from the subversion repository.

The history of my engagement with Acquia started a while ago — well, a couple of months. Considering how fast Acquia is growing, I'd call that "a while ago" around here!

Try and find the commit characters just before your commit using git log. See Image for clarification

git log

Once you have found your 6 characters. Say in our case this is 200052

git rebase --interactive 200052

Your editor will come up with several lines as seen in the image. If you not familiar with the default editor (probably vim) you should press i before you can edit

First step in the MIT building, ever!

Yesterday (4Th. of October) I decided to take part of the local Drupal User Group here in Boston. It took place in a room from the MIT university. And faith decided I was lucky because it seemed I was part of an experiment! Lucky might not be the best way to describe it, surely when you don't know what the experiment is *wink*

Since I am trying to figure out how to work, in the most efficient way, with the issue queue in Drupal I came accross a really useful application from github named github for mac :