"trunk" is ambigous

[Mike Alexander]

I've been trying to set things up to use the git mirror of the 
subversion repository for GnuCash as described on the wiki.  I 
submitted a trivial patch last night to make sure things were working 
ok.  They seem to be fine, but git keeps complaining "warning: refname 
'trunk' is ambiguous" when I do things like git-update or git checkout 
trunk.  I think I followed the instructions on the Wiki, but I must not 
have.  Does anyone know what I did wrong or how to fix it?  Although 
things seem to be working I wonder if this is a symptom of a problem 
that will cause trouble later.

             Mike