Working Jython and Python Slack Client

_socket.py

# /opt/jython/Lib/_socket.py

SOCK_DGRAM     = 1
SOCK_STREAM    = 2
SOCK_RAW       = 3 # not supported
SOCK_RDM       = 4 # not supported
SOCK_SEQPACKET = 5 # not supported

SOL_SOCKET = 0xFFFF

IPPROTO_AH       =  51 # not supported
IPPROTO_DSTOPTS  =  60 # not supported
IPPROTO_ESP      =  50 # not supported
IPPROTO_FRAGMENT =  44 # not supported
IPPROTO_GGP      =   3 # not supported
IPPROTO_HOPOPTS  =   0 # not supported
IPPROTO_ICMP     =   1 # not supported
IPPROTO_ICMPV6   =  58 # not supported
IPPROTO_IDP      =  22 # not supported
IPPROTO_IGMP     =   2 # not supported
IPPROTO_IP       =   0
IPPROTO_IPV4     =   4 # not supported
IPPROTO_IPV6     =  41 # not supported
IPPROTO_MAX      = 256 # not supported
IPPROTO_ND       =  77 # not supported
IPPROTO_NONE     =  59 # not supported
IPPROTO_PUP      =  12 # not supported
IPPROTO_RAW      = 255 # not supported
IPPROTO_ROUTING  =  43 # not supported
IPPROTO_TCP      =   6
IPPROTO_UDP      =  17
SOL_TCP		 = 6 # Jonathan Harms

slackrequest.py

class SlackRequest(object):
    def __init__(self, proxies=None):

        # __name__ returns 'slackclient.slackrequest', we only want 'slackclient'
        client_name = __name__.split('.')[0]
        client_version = __version__  # Version is returned from version.py

        # Construct the user-agent header with the package info, Python version and OS version.
        self.default_user_agent = {
            "client": "{0}/{1}".format(client_name, client_version),
            "python": "Jython/Jonathan Harms",
            "system": "{0}/{1}".format(platform.system(), platform.release())
        }

        self.custom_user_agent = None
        self.proxies = proxies

socket.py

# /opt/jython/Lib/socket.py

from _socket import (
    socket, error, herror, gaierror, timeout, has_ipv6,

    create_connection,

    getdefaulttimeout,
    setdefaulttimeout,
    
    getfqdn,
    gethostbyaddr,
    gethostbyname,
    gethostbyname_ex,
    gethostname,
    getprotobyname,
    getservbyname,
    getservbyport,

    AF_UNSPEC,
    AF_INET,
    AF_INET6,

    AI_PASSIVE,
    AI_CANONNAME,
    AI_NUMERICHOST,
    AI_V4MAPPED,
    AI_ALL,
    AI_ADDRCONFIG,
    AI_NUMERICSERV,

    EAI_NONAME,
    EAI_SERVICE,
    EAI_ADDRFAMILY,
    
    NI_NUMERICHOST,
    NI_NUMERICSERV,
    NI_NOFQDN,
    NI_NAMEREQD,
    NI_DGRAM,
    NI_MAXSERV,
    NI_IDN,
    NI_IDN_ALLOW_UNASSIGNED,
    NI_IDN_USE_STD3_ASCII_RULES,
    NI_MAXHOST,

    SHUT_RD,
    SHUT_WR,
    SHUT_RDWR,

    SOCK_DGRAM,
    SOCK_STREAM,
    SOCK_RAW,
    SOCK_RDM,
    SOCK_SEQPACKET,
      SOCK_RDM,
    SOCK_SEQPACKET,
    
    SOL_SOCKET,
    # not supported, but here for apparent completeness
    IPPROTO_AH,
    IPPROTO_DSTOPTS,
    IPPROTO_ESP,
    IPPROTO_FRAGMENT,
    IPPROTO_GGP,
    IPPROTO_HOPOPTS,
    IPPROTO_ICMP,
    IPPROTO_ICMPV6,
    IPPROTO_IDP,
    IPPROTO_IGMP,
    IPPROTO_IP, # supported
    # not supported
    IPPROTO_IPV4,
    IPPROTO_IPV6,
    IPPROTO_MAX,
    IPPROTO_ND,
    IPPROTO_NONE,
    IPPROTO_PUP,
    IPPROTO_RAW,
    IPPROTO_ROUTING,
    IPPROTO_TCP, # supported
    IPPROTO_UDP, # supported
    SOL_TCP, # Jonathan Harms
    # supported
    SO_BROADCAST,
    SO_KEEPALIVE,
    SO_LINGER,
    SO_RCVBUF,
    SO_REUSEADDR,
    SO_SNDBUF,
    SO_TIMEOUT,
    TCP_NODELAY,

    # pseudo options

To get Slack working under Jython 2.7.0 you need to fix 3 things:

1. set the constant SOL_TCP to 6 in _socket.py
2. import SOL_TCP from _socket.py in socket.py
3. change the user-agent header so it's not trying to use the version module in the slackrequest module.