BUG: Parallel execution needs serialization

[HaoZeke]

For example:

asv run -j --launch-method spawn
· Creating environmentsTraceback (most recent call last):

  File "/home/rgoswami/micromamba/envs/asv_exp/bin/asv", line 8, in <module>
    sys.exit(main())
  File "/home/rgoswami/Git/Github/Quansight/asvWork/asv/asv/main.py", line 29, in main
    result = args.func(args)
  File "/home/rgoswami/Git/Github/Quansight/asvWork/asv/asv/commands/__init__.py", line 49, in run_from_args
    return cls.run_from_conf_args(conf, args)
  File "/home/rgoswami/Git/Github/Quansight/asvWork/asv/asv/commands/run.py", line 166, in run_from_conf_args
    return cls.run(
  File "/home/rgoswami/Git/Github/Quansight/asvWork/asv/asv/commands/run.py", line 278, in run
    Setup.perform_setup(environments, parallel=parallel)
  File "/home/rgoswami/Git/Github/Quansight/asvWork/asv/asv/commands/setup.py", line 74, in perform_setup
    pool.map(_create_parallel, environment_groups.values())
  File "/home/rgoswami/micromamba/envs/asv_exp/lib/python3.9/multiprocessing/pool.py", line 364, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
  File "/home/rgoswami/micromamba/envs/asv_exp/lib/python3.9/multiprocessing/pool.py", line 771, in get
    raise self._value
  File "/home/rgoswami/micromamba/envs/asv_exp/lib/python3.9/multiprocessing/pool.py", line 537, in _handle_tasks
    put(task)
  File "/home/rgoswami/micromamba/envs/asv_exp/lib/python3.9/multiprocessing/connection.py", line 206, in send
    self._send_bytes(_ForkingPickler.dumps(obj))
  File "/home/rgoswami/micromamba/envs/asv_exp/lib/python3.9/multiprocessing/reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
TypeError: cannot pickle 'libmambapy.bindings.Context' object

This is an upstream issue, mamba-org/mamba#3403, though it remains to be seen if it will be supported.