@task
def gitrepos(branch=None, fork='sympy'):
    """
    Clone the repo

    fab vagrant prepare (namely, checkout_cache()) must be run first. By
    default, the branch checked out is the same one as the one checked out
    locally. The master branch is not allowed--use a release branch (see the
    README). No naming convention is put on the release branch.

    To test the release, create a branch in your fork, and set the fork
    option.
    """
    with cd("/home/vagrant"):
        if not exists("sympy-cache.git"):
            error("Run fab vagrant prepare first")
    if not branch:
        # Use the current branch (of this git repo, not the one in Vagrant)
        branch = local("git rev-parse --abbrev-ref HEAD", capture=True)
    if branch == "master":
        raise Exception("Cannot release from master")
    run("mkdir -p repos")
    with cd("/home/vagrant/repos"):
        run("git clone --reference ../sympy-cache.git https://github.com/{fork}/sympy.git".format(fork=fork))
        with cd("/home/vagrant/repos/sympy"):
            run(branch % "git checkout -t origin/%s")
dataset/ETHPy150Open sympy/sympy/release/fabfile.py/gitrepos/swapped operands of `%`