I am writing a SVN to Git migration script. When I run git svn clone git-svn creates a handful of remote branches that ends in @svnrevision (for example trunk@34663).
Why are these branches created and what are they used for?
That points to latest revision of a branch that was deleted. trunk@34663 means trunk as it looked before it was deleted in revision 34664. It may have been created again in later revision, but since the state that was deleted does not have to be part of the ancestry of the new state, the deleted state is kept in this way.