# Buggy code
def file_list(load):
    """
    Return a list of all files on the file server in a specified environment
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    ret = []

    if "saltenv" not in load:
        return ret

    saltenv = load["saltenv"]
    metadata = _init()

    if not metadata or saltenv not in metadata:
        return ret
    for bucket in _find_files(metadata[saltenv]):
        for buckets in six.itervalues(bucket):
            files = [f for f in buckets if not fs.is_file_ignored(__opts__, f)]
            ret += _trim_env_off_path(files, saltenv)

    return ret


# Traceback (ValueError)
Exception occurred in runner state.orchestrate: Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/salt/client/mixins.py", line 382, in _low
data['return'] = self.functions[fun](*args, **kwargs)
File "/usr/lib/python2.7/site-packages/salt/runners/state.py", line 88, in orchestrate
orchestration_jid=orchestration_jid)
File "/usr/lib/python2.7/site-packages/salt/modules/state.py", line 1098, in sls
initial_pillar=_get_initial_pillar(opts))
File "/usr/lib/python2.7/site-packages/salt/state.py", line 3846, in __init__
BaseHighState.__init__(self, opts)
File "/usr/lib/python2.7/site-packages/salt/state.py", line 2721, in __init__
self.avail = self.__gather_avail()
File "/usr/lib/python2.7/site-packages/salt/state.py", line 2730, in __gather_avail
for saltenv in self._get_envs():
File "/usr/lib/python2.7/site-packages/salt/state.py", line 2791, in _get_envs
client_envs = self.client.envs()
File "/usr/lib/python2.7/site-packages/salt/fileclient.py", line 1331, in envs
return self.channel.send(load)
File "/usr/lib/python2.7/site-packages/salt/fileserver/__init__.py", line 892, in send
return self.fs.envs()
File "/usr/lib/python2.7/site-packages/salt/fileserver/__init__.py", line 488, in envs
ret.update(self.servers[fstr](**kwargs))
File "/usr/lib/python2.7/site-packages/salt/fileserver/s3fs.py", line 93, in envs
metadata = _init()
File "/usr/lib/python2.7/site-packages/salt/fileserver/s3fs.py", line 354, in _init
metadata = _read_buckets_cache_file(cache_file)
File "/usr/lib/python2.7/site-packages/salt/fileserver/s3fs.py", line 553, in _read_buckets_cache_file
data = pickle.load(fp_)
File "/usr/lib64/python2.7/pickle.py", line 1378, in load
return Unpickler(file).load()
File "/usr/lib64/python2.7/pickle.py", line 858, in load
dispatch[key](self)
File "/usr/lib64/python2.7/pickle.py", line 966, in load_string
raise ValueError, "insecure string pickle"
ValueError: insecure string pickle

# Fixed code
def file_list(load):
    """
    Return a list of all files on the file server in a specified environment
    """
    if "env" in load:
        # "env" is not supported; Use "saltenv".
        load.pop("env")

    ret = []

    if "saltenv" not in load:
        return ret

    saltenv = load["saltenv"]
    metadata = _init()

    if not metadata or saltenv not in metadata:
        return ret
    for bucket in _find_files(metadata[saltenv]):
        for buckets in bucket.values():
            files = [f for f in buckets if not fs.is_file_ignored(__opts__, f)]
            ret += _trim_env_off_path(files, saltenv)

    return ret