git svn fetch retrieves the same Subversion revision multiple times for branches

I noticed this question because I got the same error message:

W: Refspec glob conflict (ref: refs/remotes/trunk):
expected path: branches/trunk
    real path: trunk

It turned out that .git/config had duplicate lines that seem to confuse git-svn, like this:

[svn-remote "svn"]
...
    branches = project/branches/*:refs/remotes/*
    tags = project/tags/*:refs/remotes/tags/*
    branches = project/branches/*:refs/remotes/*
    tags = project/tags/*:refs/remotes/tags/*

Removing those duplicates solved weird git-svn behaviour for me, and might as well for you. I’m not sure what caused git-svn to duplicate this information in the first place. I killed and continued the initial clone, this might be related?