I get this assert:

File "/home/barry/wc/git/scm-workbench/Source/Git/wb_git_project.py", line 217, in canPush
for ref in remote.refs:
File "/home/barry/wc/git/scm-workbench/Source/Git/git/remote.py", line 463, in refs
assert out_refs, "Remote %s did not have any references" % self.name
AssertionError: Remote origin did not have any references

But git remote -v is happy:

$ git remote -v
origin https://github.com/barry-scott/BarrysEmacs.git (fetch)
origin https://github.com/barry-scott/BarrysEmacs.git (push)

It seems that subgit used the .git/.config file to setup the remote. Here is the .git/config

cat config 

[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
        autocrlf = false
        eol = lf
        symlinks = true
[remote "origin"]
        url = https://github.com/barry-scott/BarrysEmacs.git
        fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
        remote = origin
        merge = refs/heads/master
[gc]
        autodetach = false
        auto = 0

It seems that GitPython should be looking in config as well to find remote info but is not.