salt: salt-ssh + salt-cloud: cloud roster not working and/or `update_cachedir` is broken

Description of Issue/Question

The goal of the exercise is to provision a machine using salt-cloud and then put it into a desired state using salt-ssh. The --roster=cloud option was added to salt-ssh to assist with this. Using the script (below), we see the following behavior:

• Without update_cachedir: true:
  • [ERROR ] No matching targets found in roster.
  • VM is successfully destroyed
• With update_cachedir: true:
  • Stack trace below.
  • VMs destruction fails with No machines were found to be destroyed

[ERROR   ] An un-handled exception was caught by salt's global exception handler:
TypeError: a bytes-like object is required, not 'str'
Traceback (most recent call last):
  File "/home/bar/Dev/foo/build7/_venv/bin/salt-ssh", line 11, in <module>
    load_entry_point('salt==2017.7.2', 'console_scripts', 'salt-ssh')()
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/scripts.py", line 416, in salt_ssh
    client.run()
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/cli/ssh.py", line 20, in run
    ssh = salt.client.ssh.SSH(self.config)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/client/ssh/__init__.py", line 230, in __init__
    self.tgt_type)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/roster/__init__.py", line 105, in targets
    targets.update(self.rosters[f_str](tgt, tgt_type))
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/roster/cloud.py", line 45, in targets
    minions = __runner__['cache.cloud'](tgt)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/runners/cache.py", line 402, in cloud
    cloud_cache = __utils__['cloud.list_cache_nodes_full'](opts=opts, provider=provider)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/utils/cloud.py", line 2768, in list_cache_nodes_full
    minions[driver][prov][minion_id] = msgpack.load(fh_)
  File "msgpack/_unpacker.pyx", line 164, in msgpack._unpacker.unpack (msgpack/_unpacker.cpp:2622)
  File "msgpack/_unpacker.pyx", line 124, in msgpack._unpacker.unpackb (msgpack/_unpacker.cpp:1918)
TypeError: a bytes-like object is required, not 'str'
Traceback (most recent call last):
  File "/home/bar/Dev/foo/build7/_venv/bin/salt-ssh", line 11, in <module>
    load_entry_point('salt==2017.7.2', 'console_scripts', 'salt-ssh')()
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/scripts.py", line 416, in salt_ssh
    client.run()
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/cli/ssh.py", line 20, in run
    ssh = salt.client.ssh.SSH(self.config)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/client/ssh/__init__.py", line 230, in __init__
    self.tgt_type)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/roster/__init__.py", line 105, in targets
    targets.update(self.rosters[f_str](tgt, tgt_type))
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/roster/cloud.py", line 45, in targets
    minions = __runner__['cache.cloud'](tgt)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/runners/cache.py", line 402, in cloud
    cloud_cache = __utils__['cloud.list_cache_nodes_full'](opts=opts, provider=provider)
  File "/home/bar/Dev/foo/build7/_venv/lib/python3.5/site-packages/salt/utils/cloud.py", line 2768, in list_cache_nodes_full
    minions[driver][prov][minion_id] = msgpack.load(fh_)
  File "msgpack/_unpacker.pyx", line 164, in msgpack._unpacker.unpack (msgpack/_unpacker.cpp:2622)
  File "msgpack/_unpacker.pyx", line 124, in msgpack._unpacker.unpackb (msgpack/_unpacker.cpp:1918)
TypeError: a bytes-like object is required, not 'str'
EXIT 1

Setup

MINION_NAME='foobar-08'

AWS_ID='redacted'
AWS_KEY='redacted'
AWS_KEYNAME='redacted'
AWS_PRIVATE_KEY='redacted'
AWS_PROFILE_NAME='redacted'
AWS_SECURITYGROUP='redacted'

LOG_LVL=all

ROOT_DIR=$(mktemp -d)
CONFIG_DIR=$ROOT_DIR/etc/salt
FILE_ROOT_BASE=$(mktemp -d)

# config

mkdir -p $CONFIG_DIR

cat <<EOF > $CONFIG_DIR/cloud
root_dir: $ROOT_DIR
log_file: $ROOT_DIR/var/log/salt/cloud
update_cachedir: True
EOF

cat <<EOF > $CONFIG_DIR/cloud.providers
my-aws-default:
  id: '$AWS_ID'
  key: '$AWS_KEY'
  keyname: '$AWS_KEYNAME'
  private_key: '$AWS_PRIVATE_KEY'
  securitygroup: '$AWS_SECURITYGROUP'
  driver: ec2
EOF

cat <<EOF > $CONFIG_DIR/cloud.profiles
$AWS_PROFILE_NAME:
  provider: my-aws-default
  size: t2.micro
  image: ami-7b4d7900
  script: salt-bootstrap
  ssh_username: ubuntu
EOF

cat <<EOF > $CONFIG_DIR/master
root_dir: $ROOT_DIR
EOF

# run stuff

SLEEP=5

OPTS="--log-file-level=$LOG_LVL --config-dir=$CONFIG_DIR"

salt-master $OPTS --daemon
echo "EXIT $?"
sleep $SLEEP

salt-cloud $OPTS -p $AWS_PROFILE_NAME $MINION_NAME > /dev/null
echo "EXIT $?"
sleep $SLEEP

salt-cloud $OPTS -Q | fgrep $MINION_NAME
echo "EXIT $?"
sleep $SLEEP

salt-ssh $OPTS --roster=cloud -i -r 'uname -a' $MINION_NAME
echo "EXIT $?"
sleep $SLEEP

salt-ssh $OPTS --roster=cache -i -r 'uname -a' $MINION_NAME
echo "EXIT $?"
sleep $SLEEP

salt-cloud $OPTS -d $MINION_NAME -y
echo "EXIT $?"
sleep $SLEEP

pkill -F $ROOT_DIR/var/run/salt-master.pid
rm -rf $ROOT_DIR $FILE_ROOT_BASE

Steps to Reproduce Issue

Run the script with update_cachedir toggled.

Versions Report

Salt Version:
           Salt: 2017.7.2
 
Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: Not Installed
      docker-py: Not Installed
          gitdb: 2.0.3
      gitpython: 2.1.7
          ioflo: Not Installed
         Jinja2: 2.9.6
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.4.8
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 3.5.3 (default, Sep 14 2017, 22:58:41)
   python-gnupg: Not Installed
         PyYAML: 3.12
          PyZMQ: 16.0.3
           RAET: Not Installed
          smmap: 2.0.3
        timelib: Not Installed
        Tornado: 4.5.2
            ZMQ: 4.1.6
 
System Versions:
           dist: Ubuntu 17.04 zesty
         locale: UTF-8
        machine: x86_64
        release: 4.12.0-041200rc6-generic
         system: Linux
        version: Ubuntu 17.04 zesty