id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
712782711,MDU6SXNzdWU3MTI3ODI3MTE=,4478,Dataset to zarr not working with newest s3fs Storage (s3fs > 0.5.0),3322897,closed,0,,,15,2020-10-01T12:11:13Z,2020-12-07T14:39:57Z,2020-10-06T15:40:03Z,NONE,,,,"<!-- Please include a self-contained copy-pastable example that generates the issue if possible.

Please be concise with code posted. See guidelines below on how to provide a good bug report:

- Craft Minimal Bug Reports: http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports
- Minimal Complete Verifiable Examples: https://stackoverflow.com/help/mcve

Bug reports that follow these guidelines are easier to diagnose, and so are often handled much more quickly.
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**What happened**:
A call to zarr storage to mino instance fails with newest s3fs storage (s3fs > 0.5.0) while perfectly working with s3fs == 0.4.0. Might be due to s3fs' reliance on aiobotocore as Traceback.
```
Traceback (most recent call last):
Exception in callback <TaskStepMethWrapper object at 0x7fbe34300350>()
handle: <Handle <TaskStepMethWrapper object at 0x7fbe34300350>()>
Traceback (most recent call last):
  File ""/usr/local/lib/python3.7/asyncio/events.py"", line 88, in _run
    self._context.run(self._callback, *self._args)
RuntimeError: Leaving task <Task finished coro=<sync.<locals>.f() done, defined at /usr/local/lib/python3.7/site-packages/fsspec/asyn.py:43> result=None> does not match the current task None.
  File ""test_without.py"", line 27, in <module>
    array.to_dataset().to_zarr(store=s3store, mode=""w"", consolidated=True, compute=True)
  File ""/usr/local/lib/python3.7/site-packages/xarray/core/dataset.py"", line 1662, in to_zarr
    append_dim=append_dim,
  File ""/usr/local/lib/python3.7/site-packages/xarray/backends/api.py"", line 1369, in to_zarr
    writes = writer.sync(compute=compute)
  File ""/usr/local/lib/python3.7/site-packages/xarray/backends/common.py"", line 161, in sync
    regions=self.regions,
  File ""/usr/local/lib/python3.7/site-packages/dask/array/core.py"", line 981, in store
    result.compute(**kwargs)
  File ""/usr/local/lib/python3.7/site-packages/dask/base.py"", line 167, in compute
    (result,) = compute(self, traverse=False, **kwargs)
  File ""/usr/local/lib/python3.7/site-packages/dask/base.py"", line 452, in compute
    results = schedule(dsk, keys, **kwargs)
  File ""/usr/local/lib/python3.7/site-packages/dask/threaded.py"", line 84, in get
    **kwargs
  File ""/usr/local/lib/python3.7/site-packages/dask/local.py"", line 486, in get_async
    raise_exception(exc, tb)
  File ""/usr/local/lib/python3.7/site-packages/dask/local.py"", line 316, in reraise
    raise exc
  File ""/usr/local/lib/python3.7/site-packages/dask/local.py"", line 222, in execute_task
    result = _execute_task(task, data)
  File ""/usr/local/lib/python3.7/site-packages/dask/core.py"", line 121, in _execute_task
    return func(*(_execute_task(a, cache) for a in args))
  File ""/usr/local/lib/python3.7/site-packages/dask/array/core.py"", line 3722, in store_chunk
    return load_store_chunk(x, out, index, lock, return_stored, False)
  File ""/usr/local/lib/python3.7/site-packages/dask/array/core.py"", line 3711, in load_store_chunk
    out[index] = np.asanyarray(x)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1115, in __setitem__
    self.set_basic_selection(selection, value, fields=fields)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1210, in set_basic_selection
    return self._set_basic_selection_nd(selection, value, fields=fields)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1501, in _set_basic_selection_nd
    self._set_selection(indexer, value, fields=fields)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1550, in _set_selection
    self._chunk_setitem(chunk_coords, chunk_selection, chunk_value, fields=fields)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1665, in _chunk_setitem
    fields=fields)
  File ""/usr/local/lib/python3.7/site-packages/zarr/core.py"", line 1729, in _chunk_setitem_nosync
    self.chunk_store[ckey] = cdata
  File ""/usr/local/lib/python3.7/site-packages/fsspec/mapping.py"", line 150, in __setitem__
    self.fs.mkdirs(self.fs._parent(key), exist_ok=True)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/spec.py"", line 1066, in mkdirs
    return self.makedirs(path, exist_ok=exist_ok)
  File ""/usr/local/lib/python3.7/site-packages/s3fs/core.py"", line 488, in makedirs
    self.mkdir(path, create_parents=True)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 118, in wrapper
    return maybe_sync(func, self, *args, **kwargs)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 97, in maybe_sync
    return sync(loop, func, *args, **kwargs)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 68, in sync
    raise exc.with_traceback(tb)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 52, in f
    result[0] = await future
  File ""/usr/local/lib/python3.7/site-packages/s3fs/core.py"", line 462, in _mkdir
    if not key or (create_parents and not self.exists(bucket)):
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 118, in wrapper
    return maybe_sync(func, self, *args, **kwargs)
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 90, in maybe_sync
    return _run_until_done(func(*args, **kwargs))
  File ""/usr/local/lib/python3.7/site-packages/fsspec/asyn.py"", line 28, in _run_until_done
    loop._run_once()
  File ""/usr/local/lib/python3.7/asyncio/base_events.py"", line 1771, in _run_once
    handle = self._ready.popleft()
IndexError: pop from an empty deque
```
**What you expected to happen**:

Storage succeeding. No Exception.

**Minimal Complete Verifiable Example**:

```python
# Put your MCVE code here
import dask.array as da
import xarray
import s3fs
import xarray as xr

bucket = ""zarr""
name = ""sample""

nana = xarray.DataArray(da.zeros((1023,1023,3)))

s3_path = f""{bucket}/{name}""
s3 = s3fs.S3FileSystem(client_kwargs={""endpoint_url"": ""s3://minio:9000""}, username=""weak_access_key"", password=""weak_secret_key"")
s3store = s3.get_mapper(s3_path)


print(""Storing"")
nana.to_dataset().to_zarr(store=s3store, mode=""w"", consolidated=True, compute=True)
print(""Getting"")
```

**Anything else we need to know?**:

Thanks and keep up the great work!

**Environment**:

dask==2.28.0
xarray==0.16.1
aiobotocore==1.1.1
fsspec==0.8.3
zarr==2.4.0
s3fs==0.5.1

<details><summary>Output of <tt>xr.show_versions()</tt></summary>

<!-- Paste the output here xr.show_versions() here -->
INSTALLED VERSIONS
------------------
commit: None
python: 3.7.8 (default, Jun 30 2020, 18:27:23) 
[GCC 8.3.0]
python-bits: 64
OS: Linux
OS-release: 4.19.104-microsoft-standard
machine: x86_64
processor: 
byteorder: little
LC_ALL: None
LANG: C.UTF-8
LOCALE: en_US.UTF-8
libhdf5: None
libnetcdf: None

xarray: 0.16.1
pandas: 1.1.2
numpy: 1.19.2
scipy: 1.5.2
netCDF4: None
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: 2.4.0
cftime: None
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: 2.28.0
distributed: 2.28.0
matplotlib: 3.3.2
cartopy: None
seaborn: 0.11.0
numbagg: None
pint: None
setuptools: 47.3.1
pip: 20.1.1
conda: None
pytest: 6.1.0
IPython: 7.18.1
sphinx: None

</details>
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