SaltStack ssh_auth_sources - TypeError: coercing to Unicode: need string or buffer, bool found

output.txt

minion2:
    ----------
    file_|-users_/etc/sudoers.d/whfit_|-/etc/sudoers.d/whfit_|-absent:
        ----------
        __run_num__:
            7
        changes:
            ----------
        comment:
            File /etc/sudoers.d/whfit is not present
        duration:
            0.252
        name:
            /etc/sudoers.d/whfit
        result:
            True
        start_time:
            18:58:51.090055
    file_|-users_whfit_user_|-/home/whfit_|-directory:
        ----------
        __run_num__:
            5
        changes:
            ----------
        comment:
            Directory /home/whfit is in the correct state
        duration:
            0.572
        name:
            /home/whfit
        result:
            True
        start_time:
            18:58:51.082686
    group_|-users_whfit_user_|-whfit_|-present:
        ----------
        __run_num__:
            3
        changes:
            ----------
        comment:
            Group whfit is present and up to date
        duration:
            0.411
        name:
            whfit
        result:
            True
        start_time:
            18:58:51.081046
    pkg_|-common_packages_|-common_packages_|-installed:
        ----------
        __run_num__:
            0
        changes:
            ----------
        comment:
            All specified packages are already installed.
        duration:
            330.634
        name:
            common_packages
        result:
            True
        start_time:
            18:58:50.708108
    pkg_|-git_|-git_|-installed:
        ----------
        __run_num__:
            2
        changes:
            ----------
        comment:
            Package git is already installed.
        duration:
            3.711
        name:
            git
        result:
            True
        start_time:
            18:58:51.075002
    pkgrepo_|-git_repo_|-deb http://ppa.launchpad.net/git-core/ppa/ubuntu trusty main_|-managed:
        ----------
        __run_num__:
            1
        changes:
            ----------
        comment:
            Package repo 'deb http://ppa.launchpad.net/git-core/ppa/ubuntu trusty main' already configured
        duration:
            34.73
        name:
            deb http://ppa.launchpad.net/git-core/ppa/ubuntu trusty main
        result:
            True
        start_time:
            18:58:51.039973
    ssh_auth_|-users_ssh_auth_source_whfit_0_|-users_ssh_auth_source_whfit_0_|-present:
        ----------
        __run_num__:
            6
        changes:
            ----------
        comment:
            An exception occurred in this state: Traceback (most recent call last):
              File "/usr/lib/python2.7/dist-packages/salt/state.py", line 1560, in call
                **cdata['kwargs'])
              File "/usr/lib/python2.7/dist-packages/salt/states/ssh_auth.py", line 217, in present
                saltenv=__env__)
              File "/usr/lib/python2.7/dist-packages/salt/modules/cp.py", line 303, in get_file_str
                with salt.utils.fopen(fn_, 'r') as fp_:
              File "/usr/lib/python2.7/dist-packages/salt/utils/__init__.py", line 1045, in fopen
                fhandle = open(*args, **kwargs)
            TypeError: coercing to Unicode: need string or buffer, bool found
        duration:
            6.337
        name:
            users_ssh_auth_source_whfit_0
        result:
            False
        start_time:
            18:58:51.083629
    user_|-users_whfit_user_|-whfit_|-present:
        ----------
        __run_num__:
            4
        changes:
            ----------
        comment:
            User whfit is present and up to date
        duration:
            0.942
        name:
            whfit
        result:
            True
        start_time:
            18:58:51.081578

pilar.sls

users:
  whfit:
    fullname: WHF IT
    password: $6...........
    sudo_rules:
      - ALL=(ALL) NOPASSWD:ALL
    ssh_auth_sources:
      - salt://files/ssh_keys/aab-rsa.pub