Scripted clone generating an incomplete, unusable .git/config

This is a weird issue I ran into while scripting some Git operations
with git 1.7.2 on a Linux server.

When running the git-clone command manually from the command line, the
resulting repo/.git/config had all three required sections: core,
remote (origin), branch (master).

When running the exact same git-clone command manually from the Python
scripted, the resulting repo/.git/config was missing the `core` and
`remote` sections.

Here's a bash log fully demonstrating the issue:

  $ python -c "import os; os.popen('git clone
git@git.domain.com:repos/repo.git')"
  [...]
  $ cat repo/.git/config
  [branch "master"]
          remote = origin
          merge = refs/heads/master
  $ rm -Rf repo
  $ git clone git@git.domain.com:repos/repo.git
  $ cat repo/.git/config
  [core]
          repositoryformatversion = 0
          filemode = true
          bare = false
          logallrefupdates = true
  [remote "origin"]
          fetch = +refs/heads/*:refs/remotes/origin/*
          url = git@git.domain.com:repo/repo.git
  [branch "master"]
          remote = origin
          merge = refs/heads/master

What's causing this?  Is it a bug?

Thanks, D