Argument "q" of both targets is the same and is given by main process.

########################################
# IN LOADER PROCESS
########################################
...
import builtins
...

def get_descriptor(f):
    c = f.__code__
    globals_ = { }
    builtins_ = []
    for name in c.co_names :
        if not name in dir(builtins):
            globals_[name] = f.__globals__[name]
        else:
            builtins_.append(name)
    return (c.co_argcount,
            c.co_kwonlyargcount,
            c.co_nlocals,
            c.co_stacksize,
            c.co_flags,
            c.co_code,
            c.co_consts,
            c.co_names,
            c.co_varnames,
            c.co_filename,
            c.co_name,
            c.co_firstlineno,
            c.co_lnotab), globals_, builtins_

def _loader(..., q, ...):		# this is loader/writer target
    ...
    # kind is instance of type
    # plugin is loaded by YAPSY, it is instance of PluginInfo
    # meta is dict with strings as both keys and values
    print("Putting tuple", (kind, plugin, meta), "in serialized form")	# line 87 of loader_process.py
    def x():
        print("doing x")
        val = (kind, plugin, meta)
        print("val", val)
        return val
    q.put( get_descriptor(x) )
    ...

########################################
# IN CONSUMER PROCESS
########################################
 ...
import builtins
from types import CodeType, FunctionType
...

def get_function(desc):
    globals_ = {}
    for k, v in desc[1].items():
        globals_[k]=v
    for k in desc[2]:
        globals_[k]=getattr(builtins, k)
    return FunctionType(CodeType(*desc[0]), globals_)

def _consumer(..., q, ...):		#this is consumer target
    ...
    from_queue = q.get()
    foo = get_function(from_queue)		# line 25 of consumer_stub.py
    print("foo", foo)
    result = foo()
    print("result", result)
    kind, p, meta = result
    print("At", datetime.utcnow(), "plugin (", kind, ")", p, '''was loaded
    this is its metadata:''', meta)