If you are trying to use Braid, but keep getting errors of the sort:

braid: Setting up remote branch and fetching data.
braid: Error occured:
braid: Resetting braid/track to 1bb3e1a35699157e0035055306ad456f8c09b67c.
braid: Checking out branch 'master'.
braid: An exception has occured: ()

It means you are missing git-core and git-svn packages on your system. On Ubuntu/Debian it's as simple as:

sudo aptitude install git-core git-svn

To continue your work.